As someone said, 300M isn't quite right, but if you take the payment option I understand there are funds that will pay more than the lump sum payout for the rights. Let's assume after taxes we land at 200M.
20M -> long-term T-bills, this is the "never poor" fund, as these are about as stable as you can get. Should the market, my stupidity, wipe out everything else, this is always enough to retire on more than comfortably.
20M -> Mix of index, and dividend funds, draw ~3%/year for living income, which should still allow this to grow.
10M -> Go crazy money - a couple nice cars, a nice house (there's one a couple miles from me that includes a private 27acre lake for only 7M...)
150M -> Start a company to be a startup accelerator. The 150M initial capital would be invested into a mix of funds, with a goal of returning ~5M/year. This would pay the salary for a really savvy startup guy on the business side. Once a year we would run a competition for potential startups, focusing on small garage teams, the winning group would get 1M upfront, and 1M/year guaranteed for 3 years, plus the advice and contacts my business guy and I cultivate. In return we receive a 40% equity position in the company. By keeping the 150M untouched we should be able to accelerate startups indefinitely, and if say 1 in 10 can becomes worth something, it seems like that base pot should grow.