Plug Power Inc. (PLUG)

Company. Plug Power "is proof of the promise of fuel cell technology with units operating in the field, and partners around the world that are identifying customers who can put our stationary products to use today." (company website)

Buy. I bought my first lot of PLUG shares after the stock had moved up nicely and then pulled back. I thought I had gotten the timing thing down pat.

Wrong! I failed to take proper account of the three indecisive days on the run-up (short body, long tails on the candlesticks) and the fact that the high of $7.50 had actually been set on a down day with very long tails. Can we all say volatility?

Sure enough, two days later PLUG gapped down. After clawing back up to near $7, PLUG fell decisively four consecutive days; the final day opened with a big gap down and continued south on very heavy volume.

Almost inexplicably, the very next day I bought another full-sized lot of PLUG! I really don't know what I was thinking. It must have been that everybody who was going to sell had sold on 11-Nov: the volume was very heavy and the price did pull back considerably from the low during the day. It worked out that way, but truthfully, I view this as dumb luck.

Sell. My PLUG stock has had a tremendous run-up; the second lot has gained 50%. There is a lot of cushion to tolerate another pull-back. Nevertheless I decided to sell.

• The price is 22% ahead of the 50-day moving average ($5.40); that's a lot
• Yesterday's close at $7.80 was a 52-week high, and so was the day before
• My gut tells me PLUG is ripe for a bit of profit-taking (which is what I did)

I expect a pull-back followed by another rise. I intend to buy back in when that materializes, if the chart looks right.