Why do so many people talk about trading whole positions?
If you really believe in the company, but want to eliminate the risk of losing your initial investment, maybe take 1/3 to get your investment back and hold on to 2/3?
If you're not so sure of the company, maybe sell 2/3 to get some profit....and hold 1/3 to see if the momentum buyers keep running it up?
If you never believed in the company at all, then take your money and run!
"Our houses are such unwieldy property that we are often imprisoned rather than housed in them." - Henry David Thoreau, Walden: Economy, 1854