I bought my first TSLA in the $50s, but I never invested in TSLA (even though I liked it a lot) because I was certain that SPWR offered a lot better risk/reward (mainly reward) opportunity than TSLA. I had virtually 100% of my funds in SPWR in the first half of 2013 and I was right to do so:
Tesla Motors, Inc. Stock Chart | TSLA Interactive Chart - Yahoo! Finance
SPWR is up ~550% over the past year, while TSLA is up "only" ~260%. I got into TSLA a lot more in the low $100s, because by then SPWR already got a little less undervalued and TSLA still offered a lot of potential. When I say buy and hold I don't always mean to hold for ever. I buy and hold, but sell after a huge gain and shift money to a laggard. I then hold the laggard until my investment thesis proves correct.
I held on to CSIQ after it went from $16 to $11, and then all the way up to $30+. I only now sold a little CSIQ to play some of the laggards (JASO and SOL) and wait for one of those scenarios to play out. I will hold on to these until proven correct and sell only at a profit; that is what I mean when I say buy and hold. Plus CSIQ became a huge portion of my portfolio so I needed to diversify a little. If TSLA were to go to $150 next week, then it will become too big a portion of my portfolio and I would have to start hedging to free cash for other laggard opportunities.
But when I buy, I hold on the way down and expand my position to DCA for cheaper. If nothing changes in my investment thesis then I will buy more when it gets cheaper. Then when I make a big enough return only do I consider selling.
When I say buy and hold, I do not have a predetermined time frame for holding (but be prepared to hold long-term until proven correct). The sad thing is if I kept 100% of my money in SPWR I would have been better off financially than doing the thousands of trades. But I have no regrets, because trading is a ton of fun, and making money is only half of the equation; you have to have fun doing it too. Plus I learned a lot from the trades I made and it will make me a better trader in the future. Trading is an art, and the more you do it, the better you become.
Buy and hold always wins!