Buy and hold is great. These days though you can build a very inexpensive diversified portfolio of ETFs (or even index mutual funds with something like a Vanguard Admiral account if you're in the US). For example, you can get a globally diversified equity portfolio using just VT (expense ratio of 0.06%) and VXUS (0.16%). So you are paying a middleman, but only around 0.1%, and you end up with far better diversification, and far fewer securities to manage.