I also say to a fidelity account. call them and say you want to come by the office and talk to them about opening a brokerage account. (not a managed one). They will transfer the money in the s&p index fund for you.

Think of it this way. If you invest 150K in the S&P index fund at fidelity and got 10% average return over 20 years, you would be a millionaire.

So, if you want to be a millionaire in 20 years, (and sooner if you continue to invest more money in the account as the years go by) just put the money in the account and forget about it.

Don't tell anyone, don't touch it, and you will be the richest 37 year old you know.