What happened 

Shares of SunPower Corporation (SPWR -3.35%) jumped as much as 15.7% in trading Monday after getting a big upgrade from an analyst at Baird. At 1:55 p.m. EST, shares were still up 12.3%, and a few positive trends could keep shares moving higher. 

So what

Baird analyst Ben Kallo upgraded shares of SunPower from neutral to outperform and increased his price target by $3 to $10 per share. He indicated that a ramp-up in P-Series production and the sale of 8point3 Energy Partners (CAFD) could drive shares higher. 

Utility scale solar installation in a grassy field.

Image source: SunPower.

The other notable news item today was an offer by Canadian Solar's (CSIQ -3.56%) CEO to take the company private. This follows JA Solar, Trina Solar, and Renesola all either being taken private or agreeing to a deal recently. It's another indication that executives think the industry is undervalued, and they're willing to put their money where their mouth is. 

Now what

The upgrade is a positive data point for investors who are bullish on SunPower (like myself), but buying on an upgrade alone isn't a good move. What investors should look for in the next few months is an actual announcement that SunPower is selling its stake in 8point3 Energy Partners, the sale of projects being developed in Mexico, and signed contracts for P-Series solar panel sales. If those three things come together, SunPower's stock could continue today's surge. But there's been hype around the company before -- and investors should look for concrete improvements rather than speculation given past disappointments.