He's done this before. He had a good run form 2000-2009 but then had a bad run and liquidated his fund to manage his own money.
he restarted a fund in 2013 and managed a relatively small amount of money(200M) and has had mixed results. He announced last month he's liquidating his fund but also left a teaser that he'll make an announcement on Nov 25th.
I think the one big lesson I've personally taken from him for money management is the saying that "right but early is still wrong". He was right in 2008 but nearly lost regardless.
Now he's made big bets on water, the ai boom ending and the age of free money for companies from the government ending, Palantir as a company wouldn't exist without copious amounts of government money, Thiel's bet on cozying up to Trump really paid off here..
He may be right on all 3 but he was early and therefor from an investing standpoint he was wrong.
With him and the rest of the old guard of short funds (Chanos, Kynikos and Hindenburg) all closing up shop it also proves the old adage that you can't fight the fed and when they pump out so much free money like they did from 2008 till now that its very hard to be short as even terrible companies can limp along forever.
I'll be watching closely to see what he does with his next act.