DeFi currently lives on Ethereum. Even though there are other platforms with DeFi applications, Ethereum is by far the leader in the space. I think this is due to two big reasons:

Bitcoin, for example, has the network effects (and the strongest computational network) but didn't have a smart-contract platform that allowed devs to build things on top of it. All other smart-contract platforms have much weaker network effects leading to significantly lower development and adoption of DeFi on those platforms (although I think this is changing pretty quickly).

I've recently been seeing a lot of talk about DeFi on Bitcoin, so I thought I'd do a deep dive and share my learnings here. The first question to ask will be if Bitcoin doesn't have smart contracts, how can we enable activities like lending, borrowing, derivatives etc.? This is happening using a concept called pegged sidechains. Pegged sidechains are essentially separate blockchains without a native currency. They use a version of the native currency of their parent chain (i.e. Bitcoin). Users can transfer bitcoin (the currency) from the Bitcoin network to the sidechain (this happens via a lockup of the currency on Bitcoin and the issuance of an equivalent token on the sidechain). So, new sidechains can enable better tech without having to create a completely new ecosystem themselves. This better tech includes faster, cheaper transactions and a smart-contract platform to enable DeFi. The two sidechains on Bitcoin that stand out are:

The most promising sidechain project, in my opinion, is, Sovryn (built on top of RSK). Sovryn has a dApp with borrowing, lending and margin trading activities available. Using their dApp gives me the highest confidence compared to other projects with similar offerings on RSK, even though Sovryn only launched a few weeks ago. The total value locked on Sovryn has absolutely also exploded since their launch, according to this graph on RSK:

This is at least partially because it received an investment in the region of around $9 million from a group of investors led by Pomp (tweet here), causing a huge initial uptake of Sovryn and causing their governance token $SOV to almost 9x'd from the price (in sats) the investors got their allotment.

It's important to remember that it's still early days for DeFi on Bitcoin, though. I've seen many complaints on Sovryn's discord about their bridge from BTC to RBTC being excessively slow (although my transaction from FTX seemed to have gone through without any issues). The borrowing and lending program only supports 4 assets, and the use-cases, once you borrow, seem far less composable than on Ethereum. All of these growing pains will surely dissipate as Sovryn and other projects in this space mature.

If DeFi on Bitcoin does take off in a big way, I have a feeling that Sovryn might be involved, so I'll keep my eye on them over the next few months.

Coindesk article on DeFi on bitcoin: https://www.coindesk.com/bitcoin-defi-a-response

Sidechains Whitepaper: https://blockstream.com/sidechains.pdf

RSK blog on Sidechains: https://blog.rsk.co/noticia/the-cutting-edge-of-sidechains-liquid-and-rsk/