GT Solar (Nasdaq: SOLR) has become the hottest stock anywhere near the solar sector recently. After rising 64.0% in 2010, the stock is up another 39.9% so far in 2011. And it isn't solar customers powering GT Solar forward anymore.

On Friday, the company announced that it had received a $460.4 million order for advanced sapphire crystallization furnaces from a new market entrant. This follows separate orders for $91 million and $218.9 million last month.

The latest customer apparently isn't new, but it is new to the LED market. Proliferation in this market isn't a good sign for LED makers such as CREE (Nasdaq: CREE) and SemiLEDs (Nasdaq: LEDS), which are feeling low-cost manufacturers breathing down their necks.

A Fool looks back
I've pointed to GT Solar as a top stock in the past and have even picked the stock on my CAPS page, which you can follow for yourself. But I haven't jumped into the stock with real money yet -- much to my chagrin. The stock has beaten the market by 15.1% since I made my pick on My CAPS, and it shows no signs of slowing down.

I may have missed out on an opportunity in the past, but I'm not overlooking GT Solar from here on out. The company has a history of growth and is now making smart expansions into new markets. I'll keep my CAPS pick going, and I may take a position in the stock over the next couple of weeks. The market has obviously taking notice of this stock, and it's time for Fools to stop overlooking it as well.

Even after GT Solar's incredible run, the stock isn't very expensive. Shares are trading at a forward P/E ratio of just 7.7, with $261.1 million in net cash on hand to end the last quarter. For comparison, equipment makers Aixtron (Nasdaq: AIXG) and Veeco Instruments (Nasdaq: VECO) are trading at forward P/E ratios of 22.1 and 12.9, respectively.

I'm sticking by my GT Solar pick. I think this is one of the top stocks in the market today, considering the continuously growing backlog.

Interested in reading more about GT Solar? Add it to My Watchlist, and My Watchlist will find all of our Foolish analysis on this stock.