Now that you've got your LP tokens from farming on either quickswap, sushiswap, or lending on curve, what's the best way to just set and forget it and watch your balance grow? 

There are multiple auto-compounding options (vaults) on Polygon and I'll walk through pro/cons of them below. 

• Polycat (210M TVL) - the current popular poly-(animal) farm, its token FISH has been doing pretty well. I've written more about it here
• Beefy (150M TVL on polygon, 550M overall) a primarily BSC farm that recently added polygon
• Adamant (100M TVL) has 90 day lockup for their ADDY token
• Polywhale (60M TVL) the first (?) vault on polygon, value of their token (KRILL) has collapsed recently
• Autofarm (50M on polygon, 1B overall) primarily a BSC farm that recently added polygon

There are a few more farms on polygon that I won't be covering such as polyzap (~15M TVL), polygaj (~4M TVL) and smellycat (~3M TVL) since they're new and quite small.

Intro

When you stake LP tokens on quickswap/sushiswap or lend tokens on aave/curve, you currently get an incentivized token in addition to the usual gains. For example: on Quickswap, you get QUICK + LP fees while Aave will give you MATIC + interest in same token that you deposited. To maximize earnings, you'd want to go and collect your QUICK or MATIC rewards every couple days and reinvest them (such as in Dragons Den for QUICK or lend MATIC on aave).

Farming contracts will automate the process of reinvesting but instead of re-investing the rewards in external contract, it instead sells the rewards and buys the token that you're invested in to double down on your initial investment. For LP tokens on Quickswap, this means that you'll automate the process of claiming and selling your QUICK tokens to buy more token pairs to provide more liquidity.

I've made a table above of several common vaults across the polygon platforms. IRON-USDC is the popular one atm for yield farming.

Example: Auto-compounding ETH-MATIC 

The most commonly supported pair is ETH-MATIC. If you decide to provide liquidity for the ETH-MATIC pool, you can provide them on Quickswap/Susiswap/Comethswap (however, these will have different rates when auto-compounding, I took the highest one above). You will receive LP tokens which you can then deposit in reward section of each website and will have to manually hit 'claim'. Instead you can deposit in one of the vaults listed above to automate.

At first pass, it would seem like Adamant has the highest rates. However, their gimmick is that their APR includes both ADDY rewards (their own token) as well as selling SUSHI for re-investment. Excluding ADDY (88.3%) and ADDY fee share (150%), you're only getting 39% from from auto-compounding by selling SUSHI+MATIC rewards. So a lot of it depends on how much you value the ADDY token, one big caveat to this token is that it takes 90 days to withdraw. If you want to withdraw within 90 days, you only get half of the token amount.

(it was 279% when I started this post)

Next is polywhale and it has a 1% entrance and 1% withdraw fee (which conflicts with their documentation) and 5% fee on profits (not sure if already included in APY)

Next is polycat and it has a 0.1% withdraw fee (to incentivize people to stay in their vault) and APY includes the 5% fee they take

Next is Autofarm and it has a <0.1% entrance fee with very detailed breakdown of fees and APY shown includes fees

Lastly is Beefy which has an unhelpful 'There is a 0.05%-0.1% withdrawal or deposit fee on all vaults' banner on top but their APY shown includes fees

Conclusion

Personally, I'd prefer to stick with some of the bigger TVL players like Beefy and Autofarm and I especially like how transparent autofarm is about their fees. However, they don't have very many vaults on there right now (Polycat/Adamant/Beefy win that one). It will probably come down to which pair of tokens you're providing liquidity to and if the above vaults support that token.

As always, there's additional risk (and fees) when you add another platform/strategy on top but as I outlined in a previous post the gains from compounding might make it worth it.