Also note that they had planned to repurchase up to $40 million worth of shares but it looks like instead they're opting to acquire SGI. What that means to you day traders and quant fund managers, who knows?
Well, I'm not an expert, but I've taken some finance and valuation courses. In general, stock buybacks are a way of returning cash back to investors, i.e., it's kinda like a really huge dividend. There's a couple reasons for doing this: (1) the managers think that the company is worth more than what the market values it at, or (2) the company doesn't have any available projects where it can invest the $40million. In the first case, they buy back the shares now at a cheap price, and then issue more later at a higher price. In the second case, they say "Well we're not doing anything useful with the money, you shareholders go spend it yourselves". There's other reasons for buybacks, but they're questionable as to whether they actually produce value for shareholders.
Going back to March 30, the company was only valued at $120million. It had $170 million in cash on hand, and no debt. I think it's pretty obvious that the company thought their company was worth more the market was valuing it at, i.e. it's stock was cheap, so they wanted to buy back their shares. Offhand, holding a huge amount of cash isn't very useful, since it's not a return-producing asset. Some for liquidity, yes, but not a huge amount. It's probably a good thing that they're spending it in some way.
Looking at the SGI deal, it's pretty obvious that Rackable thinks that their $25million investment is going to produce value than a stock-repurchase. They're acquiring all of SGI's assets, and they're not going to have to take on all their debt. Without looking at all the numbers, it sounds like a decent plan.
Final note, I don't follow this stock, my analysis isn't rigorous at all, and anything I say should hardly be taken as a fact. I'm just a random dude on the internet, and I'm not giving you investment advice.