Conventional thinking says that. Why does trying to avoid the big drops somehow mean you also avoid the big rises? Of course it is not possible to time each perfectly but avoiding big corrections and or crashes does an awful lot for one's returns since it takes a gain of 150% to recover from a 60% decline and so on.
Maybe you have better timing ability than some of us. For us mom and pop retails, timing the market usually resulted in getting out of syn with the market: http://www.morningstar.in/posts/41071/investor-returns.aspx
Maybe I do maybe I don't have better timing than some of you. But that link had to do with investors not traders. Traders for the most part follow things a lot more closely than the average joe and ummm here's the key part, or should I say keys to the kingdom part, use stops judiciously.
Investment is the term we use for trades that went horribly wrong- trade options,use your brains don't rely on dumb luck,because the CO of that corporation you like, will one day get caught with his fingers in the till/lying/having a love child with his secretary/ pleading insanity/ having a 'Russian' holiday