Tech stocks: BlackBerry shares surge

Shares of troubled smartphone maker BlackBerry are up nearly 7% in trading Tuesday off a positive stock upgrade and an investment from a high-profile fund manager.

According to MarketWatch, Dan Loeb and his company Third Point announced they scooped up 10 million shares in BlackBerry, which recently shook up its management ranks following poor sales of its BlackBerry 10 smartphones.

Meanwhile, The Street reports FBR Capital upgraded BlackBerry from "underperform" to "market perform," citing positive momentum.

Last fall, BlackBerry shook up its executive ranks, including replacing CEO Thorsten Heins with former Sybase chief John Chen.

In December, the company confirmed a five-year partnership with Taiwanese manufacturer Foxconn to create devices for emerging markets.

Follow Brett Molina on Twitter: @bam923.