Mostly swaps, might venture into staking and liquidity pools. Liquidity pools is lending/borrowing in de-fi right?
Sorry for the delay, I forgot to revisit this topic
Liquidity pool is different from lend/borrow
Liquidity pool you provide liquidity in 2 different coin for those who swap between these 2 coins
Lend/borrow you offer some currency to borrow some.
For example, you lend BTC to borrow USDT
- Example 1, I change the default max/unlimited value to 100 value so I do not have to spend gas fees in future to revoke this. The worse case scenario that can happen in future if I do not revoke this 100 value contract is max I can lose is $100 from a hack not a $million from my wallet address, basically I lose $100 from a $million if I do not revoke?
Exactly, you got it right
In this case only 100 dollars would be at risk
- You mentioned If the contract defaults to unlimited approval, is this still possible after I set the value with the 100 example I gave above, my 100 input value defaults back to max/unlimited again?
If you set a limit of 100, you'll make a tx and this transaction will only be on the 100
In a future transaction with the same contract you need to set it again to the desired value
- Who decided in the De-Fi world that the default input value should be set to unlimited/max and why? Who programmed this value? It is like for example banks giving their customers unlimited/max no withdrawal limits at ATM cash machines meaning if a thief has access to the debit card and there's a $million in the a account then the thief can empty all the cash from the cash machine and go onto the next cash machine and empty out and so on until balance goes to $0. It is an absolutely insane idea whoever thought of that max/unlimited input default value in de-fi. I hope there is a update to MetaMask wallet to auto adjust the default value for you for all de-fi transactions and if there is no incentive to do this then who is truly running De-Fi? Scammers/Hackers? Or they do this on purpose to collect more gas fees in de-fi from revokes.
I think they leave it at unlimited to save on fees
Some networks are cheaper, but you have to remember that transactions on the ETH network can be very expensive, and a simple transaction to approve a limit can cost several dollars, for example, making it expensive to make many transactions.
- I understand theres smart contract in de-fi that involves on-chain meaning gas fees to use the chain however Smart Signatures are supposedly off-chain meaning no gas fees so why it costs gas fees to Revoke a Smart Signature 
I can't explain this part exactly, but to revoke through revoke.cash you have to make the transaction
Alright to confirm for liquidity pools I have to provide 2 coins not just 1? Example USDT/USDC trading pair, I have to provide both of them at the same amount each not just for 1?
So in De-Fi which is the least risky way of earning the most highest passive % annual income?
Can I lend $100 USDT for bitcoin collateral and how much bitcoin LTV collateral will I get? If the borrower has $100 dollars worth of bitcoin and wants to borrow $100 of USDT then why don't the borrower just sell his bitcoin instead of getting a $100 USDT loan?
In De-Fi the borrower can default lets say a million times however there's no credit history/reports/rating of the borrower in de-fi so the borrower credit history cannot be checked on de-fi or is it bad/backlisted borrowers do not exist in de-fi because smart contracts saves the lender automatically from losses from defaults?
[quoteI]In a future transaction with the same contract you need to set it again to the desired value [/quote]
Can you give examples of same contracts for better understanding. I thought all transaction in de-fi are new transactions requiring a new smart contract each right because you always get prompts on screen from your wallet to sign/approve this and that. Or is it sites like uniswap use existing smart contracts signed by metamask in the past for new de-fi transactions?
Quote
I think they leave it at unlimited to save on fees
To confirm if I change the value from unlimited/max to 100, I have to pay gas fees again to change this value each time I transact in de-fi and if this applies to ETH then there's no escaping expensive gas fees?
Layer 2 network fees like Polygon, Arbitrum and such are much cheaper however Ethereum main chain is the strongest de-fi chain out there for that network security assurance. For example would you hold $million of USDC on the main ETH chain or on layer 2 polygon chain? What happens if for example Polygon network gets weak with its token market cap crashing in value or gets hacked because of network weakness, will the issuer of USDC Circle accept legal responsibility of this or will they say sorry you lost a $million on polygon however polygon is out of our control and we only endorse official Ethereum because we Circle use Ethereum as our backbone for our business operations, hence we cannot compensate for your losses sorry? I'm sure they must have this writing in their small print somewhere.