When is too late to switch to HF?

Definitely not too late. But the way most people approach it doesn't work.

This move is almost entirely network driven. Funds hire when they have a need and fill it through someone they trust...not job postings. So the first job is to start building those relationships now, before you need them.

Here's what most people miss - a lot of second year associates are trying to leave right now. They just got their bonus and want to go to PE, corp. dev, buy-side...some just want out. So when you get on a call with someone at a fund, "I love the markets" means nothing - they've heard it from everyone. A warm contact will only stick their neck out for you if they're confident you won't embarrass them, and "I love the markets" isn't enough to give them that confidence.

What does? You get on the call, the conversation turns to markets, and you casually deliver a tight 60 second view on a stock. Not a company description, not a CNBC soundbite - an actual thesis with a variant view. That's what piques interest and gets you the introduction. Then you follow up with a thank you and attach a tight 2-3 page write-up.

Here's the part people don't realize: that same pitch is essentially the interview. You're in a room with a PM who's going to pressure test it for 30 minutes. The stock pitch is the great equalizer — pedigree, background, timing, none of it matters if you can't deliver. So to your question on harder than coming from PE - it doesn't matter. 

You need to sound like someone who belongs in the seat right now, not a smart banker (or PE guy) looking to pivot.