Piper Jaffray Cos. beat first-quarter net earnings estimates by 33 cents a share, driven by the brokerage company's capital markets business.

The Minneapolis-based firm reported $1.10 a share in net earnings, far outpacing analysts' expectation of 77 cents. Revenue of $168.1 million beat Wall Street's estimate of $127.1 million.

Traders responded to the Thursday announcement by bidding up shares in Piper Jaffray by 99 cents, or 2.2 percent, to $45.19.

Pretax operating income in the company's capital markets business was $24.1 million, more than double last year's $10.9 million. Revenue of $141.8 million was up 60 percent.

Piper's asset management business had pretax operating income of $7.1 million, down 4 percent from a year ago, even though revenue of $19.7 million was up 8 percent.

Steve Alexander