The Dow Jones Industrial Average (^DJI -0.98%) had risen a bit more than 53 points as of 11:30 a.m. EDT. Microsoft (MSFT -2.45%) was one of the index's strongest gainers, while fellow tech stocks Zynga (ZNGA) and Marvell Technology (MRVL 4.06%) experienced notable declines.

The European Central Bank goes negative
The Dow's modest gain might have been helped by the European Central Bank's announcement this morning that it was cutting its bank deposit rate to -0.1%. That means the banks will now be charged for having their money held with the central bank.

In theory, such a move should encourage banks to lend money rather than face a new fee, helping to boost the European economy and drum up further consumption and investment. Whether this works remains to be seen, but European stocks largely rose on the announcement, and that positive momentum may have carried over to the Dow Jones.

Source: Wikimedia Commons.

Microsoft gets an upgrade
Microsoft shares rose nearly 0.7% after FBR Capital Markets raised its rating on the stock to outperform with a $49 price target. Previously, the firm had a market perform rating with a $43 price target.

FBR believes Microsoft's cloud offerings will benefit investors, and that the company's new CEO will successfully transition the Windows business to a computing era largely dominated by mobile devices. 

Zynga continues to shake up management team
Zynga shares, meanwhile, fell nearly 10% in early trading. Such volatility is typical for Zynga, which has experienced wild swings in recent months. Although shares now trade at less than $3, the stock had been worth nearly $6 in early March.

A further shake-up in the social game company's management team may have had some effect on its shares. VentureBeat reported on Wednesday that three top executives had recently left the company, which continues to try to reinvent itself. Given Zynga's struggles, new management may be a good thing, but it also suggests that this turnaround may take longer than anticipated.

Marvell stumbles
Shares of chipmaker Marvell were down more than 5% early on Thursday, though the reason was not clear. There were no major news releases of note.

Like Zynga, Marvell has been a volatile stock, but over the last six months it is still up nearly 10%. Marvell has been a favorite stock among many major investors, including hedge fund manager David Einhorn.