the best strategy for retirement investing is buy and hold. this is my
opinion. many people on this board agree with me, many don't. market timing
( trading or opportunistic investing, whatever you call it )can be done by a
small number of people, but requires knowledge and skills most people don't
have. lots of novel investors buy a fund and sell the fund when its price
rise 10%. then they miss another 20% on the way up, become greedy again, buy
again at the very top only to find market down 20%. They get nervous, sell
the fund at the bottom, and miss the next leg up. Instead of buying low and
selling high, people tend to buy high and sell low. To avoid this, people
like us, by us I mean average people, should adopt a startegy that buys and
holds a diversified portfolio and avoid market timing altogether. You can
buy a bunch of different asset classes using mutual funds or ETFs. Or you
can buy the so called target retirement funds, which are essentially
prepackaged funds that are diversified portfolios by itself. Then keep
adding money to it (DCA), till you retire.