I'll drop it at the lost and found, minus the cash. sorry but you're a sucker if you lose your wallet, I know I have been once.

Give it back to them.

I give back the wallet . I'm not interested in stealing hush money.

Why is it clear that they're a very rich banker?

I look immediately around for the person who dropped it or I call the police station and ask them how to proceed. This has happened before— although the wallet didn’t contain as much money and I don’t think the gentleman was a banker. I would NEVER keep something that didn’t belong to me.

Don’t care who it is. I’ll return it

Fuck them, take the money, don't return the wallet, just because they're a very rich banker.

It doesn’t matter if there’s five pounds or five thousand pounds in it, I’m handing it in at the nearest police station. The only other thing I might do is if it had an employee ID card in it and their building was close by. I’d take it to reception and ask if Joe Blogs worked there and hand it in to them.

I have to find the owner. I lost my wallet several times and it always was given back to me, I owe it to the "universe".

I'd take a $20 out of it to ship it to the address on the ID, hope it's up to date, or Merry Christmas to whoever lives there now I guess

I'd prefer to return their wallet to them and I can't do that if the money's missing. If I can't get in touch with them I'll keep it though.