Over the past year, the surge in M&A and private equity has boosted the stock prices of companies like Goldman Sachs (NYSE:GS) and Morgan Stanley (NYSE:MS). But not all investment banks have benefited, which is certainly the case with Thomas Weisel Partners (NASDAQ:TWPG). Still, if the tech market continues to improve, TWP's stock may get out of its funk.

In the fiscal fourth quarter, revenues increased from $75.2 million to $79.6 million, and net income increased from $7.1 million to $8.7 million. (There's no earnings-per-share comparison because, in the fourth quarter of 2005, the company was privately held.)

There was certainly lots of M&A and IPO activity in the fourth quarter, with TWP's investment banking revenues increasing 33% to $37.3 million (the biggest quarter since 2001). Some of the deals include the IPOs of Double-Take Software and Netlist, as well as advisory engagements on AT&T's (NYSE:T) sale of USinternetworking and Nomura Holdings' $1.2 billion purchase of Instinet.

TWP is also reaping the benefits from its private equity investments. That is, over the years, the firm has set up a variety of funds to invest in early-stage companies. As these portfolio investments go public or sell out, it turns into nice gains. Keep in mind that, for the typical private equity fund, the manager gets 20% to 25% of the gains.

What does this mean for TWP? Well, in the fourth quarter, the firm scored $5.9 million in earnings from private equity investments -- more than double last year.

CFO Robert West recently left the TWP. This should always be a red flag; then again, turnover is common in the financial services industry. For example, look at the recent CFO departures at Bank of America (NYSE:BAC), Citigroup (NYSE:C), and Charles Schwab.

Of course, the most critical person for TWP is Mr. Weisel, who is a legend in tech finance. In the late 1970s, he co-founded Montgomery Securities, which he sold to NationsBank in 1997.

During the fourth-quarter conference call, Mr. Weisel was definitely upbeat on the tech space. So far this year, TWP is engaged with seven IPOs and five M&A deals. The tech sector can be volatile, but if the tech bull market continues and IPOs perk up, it's probably only a matter of time until TWP's stock price gets a lift.

Further Foolishness:

Charles Schwab is a Stock Advisor recommendation. Bank of America is a Motley Fool Income Investor recommendation. AT&T is a former Stock Advisor recommendation. Try any one of our investing services free for 30 days.

Fool contributor Tom Taulli does not own shares mentioned in this article.