On The Brink with Castle Island - Esther Wong (Cashi) on Making Stablecoins Spendable (EP.743)

Episode Date: October 5, 2026

Esther Wong, founder and CEO of Cashi joins the show. Cashi is a stablecoin spending app and cashback card with a global footprint. In this episode we discuss: Customer personas and use cases for stablecoin payments The future of tokenized equities on chain The landscape of layer one and two blockchains and how these platforms converge with global stablecoin applications Cashi's roadmap and plans for the coming year To learn more about Cashi, visit their website and follow Esther Wong on X.

Today on the podcast, I sat down with Esther Wong, the founder and CEO of Cashy. Cashy is a stablecoin spending app and cashback card that lets you hold, send, and spend money globally. In this conversation, we discussed the growth of the stablecoin market, use cases in the AI economy, in the future of Stablecoin Layer 1 blockchains. I think you'll enjoy this one. So without further ado, here's my conversation with Esther from Cashie. Matt Walsh and Nick Carter are partners at Castle Island Ventures. All of these expressed by them or the guests on this podcast are

solely their opinions and do not reflect the opinions of Castle Island Ventures. Guest and host may maintain positions in the assets discussed in this podcast. You should not treat any opinion expressed by anyone on this podcast as a specific inducement to make a particular investment or follow a particular strategy, but only as an expression of their personal opinion. This podcast is for informational purposes only. Brought down by bad mortgage investments, Lehman, which has 25,000 employees, will be liquidated.

The federal government loans American International Group, AIG, $85 billion. This is a different kind of market, and the Fed is asleep. The federal government is stepping it to stabilize Fannie Mae and Freddie Mac, the two mortgage giants that have been threatened by the housing crisis. The Bank of England has pumped 75 billion pounds more into Britain's ailing economy with a new round of quantitative easing. You print a couple trillion dollars and all of a sudden people start to worry. So out of this worry, we have something called the Bitcoin. Bitcoin. Well, Esther, thank you for joining us on the brink. Thanks for having me. I'm excited.

We'd love to just hop right in. Obviously, we're going to talk a lot about stablecoins today. but tell us a little bit about Cashy and how you came to launch this business. So maybe a bit about myself, and I think that leads right into how Cash is formed. I'm from Hong Kong and Singapore. I spent around 17 years in finance, the last 10 years specifically on cut payments. So for my past two gigs is both in startups. I joined quite early.

One is a payment startup called U-Trip. They are a multi-currency card in Singapore, and the other one is Crypto.com, helping them launch the car seven years ago. So cash-y, like the concept of cashie is something that I have been thinking about for a long time. Ever since two years ago, where people started to use stable coins. And given my role, I actually worked with a lot of payment companies, for example, Visa, MasterCard. And we see this adoption, that these institutions changing their infrastructure, changing how they settle with stable coins.

So I started to look more into it. As I go deeper, I started to talk to different users. And the use case is what me and you would not really imagine in our everyday life. In Singapore, for example, we have a very sophisticated financial system. It's very easy to have access to money. But for some users, it's actually not that easy. And stable coin is their solution. So the more I look into it, the more I believe that it's actually the right time to go all in

into this concept and building for what I believe are, like very unique use case for this. group of users. So that's how I began to conceptualize about what cashie can be. And I started it this year and we are now in public beta, launching features every week and looking forward to seeing it grow and hopefully we get the adoption we hope for it. I'm always fascinated by the concept of jobs to be done. So I'm really curious when you look at your customer set, what are the real world problems that you're solving for them using stable coins. So we have hypothesis from user interviews, like different people in the team actually had different like personal experiences. So we had hypothesis. And I wanted to start off with this hypothesis

because there will be a side of the story where we are proven right or wrong. So we came in thinking that a lot of like freelancers, content creators around the world, like digital no mess, would find this product really useful because they are getting paid in either US dollar or stable points. might not have a bank account. And even if they have a bank account, they are subject to high bank fees and the latency is high. And if they are paid in local currencies, it's different worse. So we thought like this is the group of users that will use this product the most.

And as we built, we got our first initial batch of users. And we realized it's actually not really the creators yet. We are actually seeing users that likely seem to be experts coming into the platform. So we have seen a certain. nationality of users, living in a country that's different from the nationality, and just spending everyday life, buying groceries, just like making purchases online, e-commerce, Amazon, etc. I think we're still early. We're only one month into our beta. But as we promote the project, I'm hoping that we do appeal to the hypothesis that we had, like the content creators.

Because how we designed this product is also to cater for these people. We want you to be easy for you to be able to receive stable coins and then be able to either spend it or send it or draw it out. Is it mostly U.S. dollar demand that you're seeing in these customers? Is there a desire to save and spend the local currency or is this just an access to dollars type of story? Definitely demand in dollars, stable points, but different country are actually quite different. We started to look into, let's say, Venezuela users. We started to think, oh, would Venezuela users want to use the card. And we realized actually even if Venezuela user had the card,

it's hard for them to spend money with the card. One of the reasons is actually local merchants there. A lot of them don't have the pause machine. But what they have are QL codes. So it's easy for them to receive payment in QR. Then we need to change the product, right? Like we can't give them a card product if they can't even spend on merchants. And then the second reason is the local merchants there actually, the exchange rate between US dollar to local rates is actually bid. They see up to like 17% in this difference, which is another reason why people want to hold stable coin, but when they use it, they will still try use different vehicles to spend that US dollar. But the demand to hold staple coins is there.

Is there a savings use case that's also driving a lot of behavior, or is it the urge to spend on subscriptions and things like that that's driving a lot of this? Different group of users have different demands. For the content creators, people who would use this product to then make more money. We will see them using it and it's a subscription, like maybe even buying some ads and using it as a tool for mini business. But then there's also another group of users that they don't really care about our cashback campaigns. They would just use it anywhere they want. I think the convenience is part of the appeal. So there are actually different groups of users that we're starting to see emerge. There's some different patents. There's not like a one-size-a-all

item. Obviously, in the U.S. market post-Genius Act, you've started to see a lot of net new new stable coin issuers come into the market, but it's still tether and circle that dominate the lion's share of the market these days. How do consumers outside the U.S. think about which stable coin they want? I assume that they have a point of view on that. So we offer two. We offer the U.S. D.C. and U.S.T. We haven't seen any demand for the stable coins just yet. But again, our user base is so small, we're early. But we do see a preference. So for example, in Europe, USDT is now a band.

So the demand for USCC, then it's obviously much higher in that region. But for some other countries, because let's say they use a particular exchange that has a higher supply of USDT, then there will be more demand of USDT. So it's actually depend on where they get the supply from for our users. I think themselves, they don't really have a preference. It's just where there is data liquidity in their country. Do you see a world where non-U.S. stable coins become a feature of this market? I guess that's been a nascent category to date.

I've also been looking into this trend. In Singapore, we have XSGD and Brazil. There's also talks of the local resident real stable coin. The growth, if you look at the month-on-month growth of the adoption, is actually not bad. It's quite high. But in comparison, it's still quite small. I can say that we are not closing the door in any opportunities for cashy. We definitely monitor the trend and listen to customer feedback.

But at this moment, right, I don't see it as a priority for us to develop adoption beyond like US dollar stable coins at this time. There have been a number of companies that have come out with apps, super apps, if you want to call them, that have US dollar stable coins in them and then are also exploring this concept of tokenized securities and giving folks outside the US exposure to US equities or US. US real estate. Do you see that as a trend? Is that something that you're looking into? Definitely. I think the concept of this is actually quite beautiful because it's giving everyone equal access to the world's capital market, right? Whether it's US or even other countries, obviously US is

where all the attention is right now. I definitely am interested in offering this to our users, but I need to first understand what cashy user wants. If all they want is like a simple product that they can use freely without thinking too much, then the stock thing is definitely going to be happy to provide in a different way where you switch to like a pro version or something else. But the concept of it is like, I'm very aligned and it's something that I think is great. It's been interesting to see the different approaches to actually bringing those securities on chain. I think the approaches are different.

The legal structures are different. So it feels like a share of Tesla is a different thing depending on where you buy it, obviously, in the tokenized context. There was a phase in my past career where I was actually looking into how to bring it to my company's product suite. And you're right, the legal construct. I remember I had like four different options on how to structure it legally. What does it mean? Can it be traded 24-7?

Who is going to be the liquidity provider? What happens when there's a dividend? All those sort of things. So eventually when cashie needs to consider the tokenized stocks options, I think the legal aspect is also something that we will spend a lot of time. ensuring we choose the right path because like rolling back is also quite home. So obviously the infrastructure around just how to launch an app like Kashi, it's evolved a lot over the past few years in terms of the on and off ramps,

the card providers, obviously the orchestration platforms. What's the hardest part about getting something like this off the ground right now? It's not hard. I think it just depends on what you believe in because as you said, there are many providers that actually give you a whole white label. You can just get your brand up and running and use one provider, and they'll give you everything connected into the back end. The biggest name out there is Rain or TV. They have all those, like, ready-made products that anyone can just use.

And the solution is actually quite good. But for me, I went down a different route. I think it's also because I have been in this for a long time. I go really deep into the unit economics. And for me, I think building my own connections with the different core, providers is more important because I have more control and the unit economics are obviously better as well. But the downside is it takes more time. It takes connections. You need to know the people. So for me, the touch of the part is to convince my team that this is the right way to go. And

therefore, we're actually slower in launching our product. But now when it's all set up, I think it's just beautiful because we have so much more control. Yeah, that's fascinating. And obviously the unit economics, I guess, of the whole stable coin stack, it's very fluid. And I I think you've seen some compression at the orchestration layer. Owning the customer has always been a really good category, I guess. There's ways to monetize that. Do you think that in this category, it's going to be the AUM-based pricing that really drives the unit economics, or is it the transaction side?

How do you think about that? Car payments is always tricky because you have the two giants, Visa and MasterCard controlling a lot of the non-negotiables. Volume is definitely going to be very important because as you scale your volume up, then you can negotiate with the schemes to give you rebate, and that lowest you're doing economics by up to 80%. It can go to that. When I'm thinking about cashy,

obviously we won't be able to reach that scale at the start. So what can we do to actually bring us up? It's going to be the first challenge we try to tackle. AUM is relatively easy because there's so many options out there. You can hold USC and then you negotiate with a circle to get some of the yield back, or you can, you know, at the back, even launch your own stable coin and get the yield of that, right? So I would say the AUM is easier to tackle because it's more permissionless compared to

payments where there's already a lot of like infrastructure, legacy infrastructure in place that you need to negotiate with the giants. I want to dive into a little bit more on just the overlap of AI and crypto. And there's a lot of things you can do with the stable coin, I guess, in the context of AI. I think we're going to see this growth in agentic payments. But even just paying for subscriptions seems like a very logical use case for some people, paying with a stablecoin card. How are you thinking about that overlap?

But obviously, that's a fast-growing market where there is a lot of stablecoin interest. Paying for AI, the amount that we pay to AI is just going to increase. Personal hope is like the cost of the tokens will go down. But in terms of like agent making payments, I believe that you don't actually need an agent to make a payment to AI. So to me, AI subscription is no different from subscribing Netflix, Disney, Spotify, etc. I do feel that agents will get more adapted into the whole payment ecosystem. I think it will start off as being agent-assisted payments first because of the trust that humans

need to give to the agent. But as we evolve, right, as more trust is being set up, I think agents can make like recurrent payments, agent can make decisions on their own within a certain limit. And then it was slowly evolved into maybe agents can even suggest like what are the limits, what can they do? But I feel like that will be a bit further down the road, maybe like two, three years. It does feel like there needs to be almost a financial services logic with smart order routing that comes to that market just due to the runaway cost at the enterprise level, if nothing else, where there are more efficient places to route certain prompts over the course of the day.

A 100% I use my plot, my personal plot, to help me route for, not the cheapest,

but like the site note, if I sample I'm trying to find a certain bottle of wine, then I'll ask to help me,

hey, this is the bottle of wine that I like, can you help me find the best pay to buy it? Then the clock will come back and say,

okay, this bottle of wine is like $70 on this website. It's already the cheapest. But if you like this type of wine, there's an alternative

that you can consider it's not the same bottle, but it's safety. So you'd be like, wow, it's like having a sales person, in front of you because it doesn't just execute what you ask for. It actually provides you alternative that you can consider.

So it's amazing. Well, what I really want is the layer that sits above Claude and lets me know that for what I'm asking, I should be routing to an open source model and maybe making a stable coin payment for that as opposed to using the frontier for something that doesn't need to be at the frontier. I think that would be like super interesting. But building that frontier layer is going to require kind of like more potty to agree on it. Like, for example, the merchants needs to accept it because for the merchant, they have more

considerations. What if this dispute? What if the person at the end doesn't agree to this transaction? Is the agent responsible who is going to pay for it? I think it's like those are the nitigrities that we get into when we want to make this beautiful world of like really smooth transactions. In payments, it's always the fraud that you need to spend the time to plan about. Speaking of that, what does that look like in the context of stable coins or the, fraud losses, you know, better or worse? How does that compare to legacy payments? I would say the same for the card payments, which is what Tashi is doing right now.

If you're talking about like non-car payments, right, not payments to merchants, but just like P2P payments, then definitely it's much easier to have fraud in stable coins or crypto in general because you don't go through a centralized bank that can crawlback or help you frees the other persons, the town, et cetera. Once the scent on chain is gone, there's no anyone to help you crawl back that amount. There's definitely been this trend that we're seeing in Latin America in particular, where remittance companies are really thriving with stable coins, but in some cases, the end user doesn't even really need to know that there's a stable coin powering that payment.

It just feels like a frictionless digital payment that happens to settle on stable coins. How do you think about that? I mean, is success here in the category, just the fact that everyone is using a dollar, and doesn't know if it's on ACH or if it's a wire behind it or if it's a stable coin? Definitely. In Latin America, people don't even call them stable points. They call them digital dollar. They don't know what chain the dollar is sent on.

They don't need to know. They just need to know that if I initiate like a transfer, it can start from ACH and it reaches my account. I can see the U.S. dollar value. I don't need to know whether it's at USCT or U.S.EC and what chain it sits on. And when I want to spend it, I can just spend it like digital dollar. I think we're already there. Like, this is how people see it.

This is how people in Latin America see stable coins. Yeah, I think that's spot on. It's also going to be really interesting to me to see how just the competition emerges between the stable coin issuers and the chains. You're seeing Circle launched their own chain. I think that launched this morning. Obviously, Stripe is launching tempo. It seems like that will have a token.

How do you think about just the market structure of who's competing with whom? This is a tough question. I think at some point, like some of the exchanges also think about their own stable coins, some launch their own stable coins as well. I think to me, maybe I'll speak from the behalf of, like,

as an end user, I would only care if the stable coin I have has the liquidity and it's actually remaining the stable. We all went through what happened with Luna. For some people, it left like a bad taste in stable coins or, And that's all, right? So to me, it's about like, do you trust this? It's almost the same as today's currency. Like, there's a high demand for US dollars because everyone trusted. They believe that

it's a strong currency. And then there are countries that there's hyperinflation, right? So to me, I feel like it's same, same, but different or like different stable point issuer. I'm going to just be really interested to see how the economics work for the tokens that power some of these blockchains. You know, you have these consortium chains, emerging. What is the reason to own that token? Are there cash flows coming off of the transaction network that get shared? It's almost like a modern-day visa network in some ways, I guess. Maybe there is a playbook there, but it'll be interesting to see if that is a durable playbook in the stable coin market where you could, of course, just send it on really any

blockchain. You know, the switching costs seem to be quite low. That is an interesting question, because in my line of work, I talk to a lot of different chain, like ecosystems and all the chains are trying to bring liquidity onto their chain. So there's more liquidity, then you can raise funds. But again, then you have the token, right? You have the token for that chain as guests. You don't actually need that much gas token in today's world. Then what's the point of owning the token?

Is it really a utility or are you buying it for speculative purposes? I think a lot of people, when they buy a token of a chain, is really for speculative purposes. Then you'll have to ask yourself, does having stable points apply on that chain actually will include the token? I think I have not seen any evidence of this happening, but crypto has always been able to amaze me, I can see for sure, whether one chain will actually come out suddenly

and have a token release and that token will appreciate so much because of stable point adoption. I don't think so, but I'm not going to worry. would happen. Yeah, I think what we've seen in this industry is definitely that the money use case for the native L1 token is the dominant one. And that is speculation. It's maybe a like a venture bet on the emergence of a non-sovereign money on some of these chains. Bitcoin's the best example of that, I suppose. But you're right in terms of the translation from usage into what the token ought to be worth, look at Robin Hood chain. It's built on Arbitrum and then obviously on top of

Ethereum, but you don't really need that much of those native tokens in order to power it, and all of the values occurring to Robin Hood. So it's kind of a head scratcher. It's really not driving any value to the L1 or the L2, I would argue. It's not, but it's a good story. I think that's all I can say. The chain token, it was a different story a few years ago, compared to now. I think people have seen it play out. I think during the D5 summer a few years ago, we do see thing like phantom chain and avalanche. All those chain tokens aren't really high because of like certain use things. It was defypropos back then, NFTs back then.

Maybe stablecoin can be the next driver. It's just hard for me, having been through all those, to imagine this becoming a reality, given what we already know. I wanted to talk to you a little bit about just the usability and the product experience. It seems like the stablecoin market generally has been at the front edge of this market in terms of making these products more usable, making them feel like traditional payment rails in some respects in the positive ways, not the negative ways of like sending a wire.

But how do you think about it just from a product perspective in terms of pleasing customers that might not come from a crypto-native background? This is exactly what we're building towards. How can we enhance the user's experience of spending dollars? We don't really need to emphasize that this is on blockchain. It's just like on product, what can we then turn on? And I think because of stable coins and because of blockchain, a lot of the nuances, you can actually get rid of it.

So for example, there are many providers out there that is like an orchestrator layer. And for me, for example, if I want to accept a user in Colombia to buy stable coins in order to use it on the platform, it would have taken me months to set up a local Colombian account for the users to deposit Colombian dollars to me, and then for me to build the technology behind reading that instantly and crediting users' USC Insane. But now because of blockchain

and because of stable coins, a lot of that can be quite smooth because you can have orchestrators. And then the real Fiat, Colombian dollars can just be swapped within the providers' own balance sheet and own asset ledger into what is needed to provide me. They don't actually need to send me the money, but that digital as I can just

be transferred to me like almost instantly and very cheaply on chain. So I think that there's the beauty. You can achieve globalization much more quickly without having to actually be physically there. I mean, it's such an interesting time to be building a global business right now with AI tools. I'd imagine just even the language and what shows up on the screen for the customer based on geographies. You can be a lot more efficient at knowing what's a good idea and what's a bad idea from a product perspective by using these tools? Exactly, 100%. When we launched Kashi, I still remember my early days of building a product.

Adding a new language is so many nuances. You actually need a lot of people to vet it, looking through all the 50 screens, for example. Right now with AI, you are 80% done. We do have people in the community to help us fine-tune it, but you're 80% done. And the pages, like, for example, you know, in three layers, within the setting and something else, it's fine if the language is not perfect, as long as it's accurate, right, with AI translation.

And now we can support, I think we just added two more languages in our next release. So I'm very excited. I can just edit within one week. One of the things that I've been saying for years is that I think stable coins are going to grow to such an exceptional scale that you're going to have local governments in some of these countries get really threatened. and they're going to think that their fiat currency is at risk. And I think we're already seeing this in a lot of hyperinflationary regimes.

But how do you think about that? I mean, what is the logical response to stable coins by some of these countries that are losing control of their local fiat? This is a really tough one. There are hyperinflation countries that is obviously right now very threatened. And there's also, like China, for example, they've always been controlling the outflow, right? So what is the response for them? Honestly, I don't know. Because if they were to embrace it, then there's a lot of like repegging.

Like how do you even say that, hey, I want to support like stable coins, but how do I translate my currency into stablecoin? And is that stable coin U.S. dollar denominated or my currency? If it's my currency, I don't think users will want it, honestly. Right. I feel like the reason why stable coin took off is because it's denominated in. US dollar and people actually want to hold US dollar. But in the past, there's just no easy way to get a lot of that US dollar. I mean, you've seen dollarization events before stable coins in certain countries, but it was bags of $100 bills. This is just a lot easier. And I guess in

a lot of respects, that's a great thing for individual rights, you know, the ability to store your wealth and your own chosen currency. But it makes it a big challenge if you're running a government that has a 10% plus inflation, you can't control the currency. And it, you can't control the currency. way you used to. So I'm glad I'm not a politician. Yeah, right. Shutting down the internet doesn't seem like a great option either, right? So I guess it's all to the benefit. People will always find ways around it. They have a tough job, like those countries. I would love to see what happens. So Esther, this has been great. What is next for the few months here at Cashie? What do you focus on? And where can we send people to get smarter about the

company? I think on the user side, they can expect to see more rewards when they're using the So we have a 321 cashie campaign. So we give 3% to subscriptions, 2% on e-commerce and 1% on travel. The reason why is like 3-2-1 is because this is sustainable for us. We don't go up to like, you know, 20% cash-5 or something else because it's not sustainable. So we try to keep it very simple, right? When they think about cashie, oh, it's a 3-2-1 campaign. And then every week we try to add more merchants to the list and it can be very localized.

So I would say if you're a cashier user, please feel free to share your feedback and say, hey, I use this in Japan a lot when you consider it. And obviously, we will think about it as long as it works for us so we can have a win-win with us and the user. So yeah, that's like one of the consumer things that you can expect to see in the next few months. And then the second thing is agent-tick assist the payment,

something personally I'm very excited about. I want cashie to be a service, not just an app to the users. So if you are a very AI savvy users, you can connect your AI tool, whether it's chat GPT, whether it's plot or something else, Gemini. You can just say, hey, help me buy this or that, or help me even find this and that. And do you want to pay? Just use the MCP and connect to cash-y. Then you don't even need to open the cashier.

You can just make the payment and go straight through. I think this will be super beneficial to users who are always at their computer or using AI a lot. It just makes the payment much more easier. On the catchy side, not super relevant for the users, but we are continuing to go down the path of getting out more licenses so that we can offer more products and service to our users. We're looking to add yield down the road, maybe even tokenized stocks,

but we just want to make sure that we have all the licenses in place so that there's no disturbance once we start providing this service. Those are top of mind for me. I'm sure there's a lot more. Maybe when I go back, my team will be like, Esther, you didn't mention this and that. But yeah, these are the big things, right? These are the big things. We are doing weekly releases.

So if you're interested, please follow our social. That's awesome, Master. Well, this has been a great rundown of the staple coin space. And congratulations on the launch. And thanks for joining us on the brink. Thank you so much, Matt. This is great. Thank you for your time.

Thanks for listening to another episode of On the Brink with Castle Island. To learn more about Castle Island, visitcastle Island. And to listen to all of our podcast episodes, please visit castle island.vc. podcast or just click on the tab on our website. Thanks for listening.