Boston-based Castine Capital Management LLC increased its investment in the financial services sector to $294.4 million as of Dec. 31, 2017, up from $271.0 million a quarter earlier, according to the firm's most recent Form 13F filing.

The hedge fund also revealed four new investments, including an $11.4 million position in Cambridge, Mass.-based Cambridge Bancorp, which became its ninth-largest position as of year-end. Two other initiations, Billings, Mont.-based First Interstate BancSystem Inc. and Carmel, Ind.-based Merchants Bancorp, also became top 20 holdings, while Downingtown, Pa.-based DNB Financial Corp. became Castine's second-smallest holding at $1.2 million.

Castine increased its stake in McKinney, Texas-based Independent Bank Group Inc. by 57.7% during the fourth quarter, pushing its total investment to $13.0 million as of Dec. 31, 2017. On Nov. 28, 2017, Independent Bank Group announced that it would acquire Houston-based Integrity Bancshares Inc. for $161.5 million.

Castine's position in Sterling Bancorp more than tripled in the fourth quarter to $13.3 million, making the company its second-largest holding. The hedge fund sold off much of its investment in Sterling during the third quarter and initiated an $8.6 million position in Astoria Financial Corp., which Sterling had agreed to buy earlier in 2017 in an all-stock deal. The acquisition closed Oct. 2, 2017.

In addition, Castine completely sold out of a $4.9 million stake in Santander Consumer USA Holdings Inc. and a $4.6 million stake in Hamburg, N.Y.-based Evans Bancorp Inc.

S&P Global Market Intelligence offers a variety of tools to help analyze the institutional holdings of a company. Click here for a template that allows users to analyze Castine Capital's common stock holdings as of Dec. 31, 2017. Click here to view Castine Capital's current common stock holdings. Company filings including the Form 13F can be found through the filings archive on a company's briefing book page.