Every quarter, many money managers have to disclose what they've bought and sold via 13F filings. Their latest moves can shine a bright light on smart stock picks.

Today let's look at Columbia Wanger Asset Management. Founded in 1992, it's a subsidiary of Ameriprise Financial, managing mutual funds and serving investment companies, pension plans, and others. Its reportable stock portfolio totaled $26.1 billion in value as of Dec. 31, 2013.

Interesting developments
So what does Columbia Wanger's latest quarterly 13F filing tell us? Here are a few interesting details:

The biggest new holdings are aerospace simulation specialist CAE and Groupon, Inc. Other new holdings of interest include Celldex Therapeutics (NASDAQ:CLDX) and RE/MAX Holdings (NYSE:RMAX). Celldex shares more than tripled over the past year, making it one of 2013's best-performing biotechs, largely because of excitement over its late-stage brain cancer immunotherapy treatment, rindopepimut. The company has seen great promise in some of its formulations, with more in its pipeline. Cash burn, addressed via stock dilution, has been a concern, but with biotech companies, potential FDA approvals are the keys to ultimate success, and additional stock issuances aren't necessarily regrettable.

Real-estate brokerage franchisor RE/MAX Holdings went public in October, with bulls hopeful about its prospects as the housing market improves in the U.S. -- and also in Japan, where RE/MAX has been expanding. The company's third quarter featured its agent count rising 4% over year-ago levels to 92,731, and revenue up 5%, to $40.3 million. Management sees agent growth as its prime growth-driver and is also aiming to expand internationally.

Among holdings in which Columbia Wanger Asset Management increased its stake was Sarepta Therapeutics (NASDAQ:SRPT). After getting whacked by an FDA decision, Sarepta recently surged nearly 40% on good data from a phase IIb study of its experimental Duchenne muscular dystrophy drug, eteplirsen. That, along with its valuation, led to an upgrade from analysts at Needham, from hold to buy. If FDA approval is eventually granted, Sarepta Therapeutics may turn out to be a strong winner for investors.

Columbia Wanger Asset Management reduced its stake in lots of companies, including Windstream Corporation (OTC:WINMQ) and BioMarin Pharmaceutical (NASDAQ:BMRN). Windstream has seen its stock slide in recent years -- as its future presents considerable uncertainty -- but many investors remain interested, probably because of its dividend yield, which tops 13%! Its revenue has been growing, but that hasn't been reflected very well in the bottom line, with profit margins and earnings shrinking. Facing a shrinking landline business and losses of customers, Windstream has been shifting its focus from rural telecom service toward broadband service, cloud computing, and business customers. Questioning its dividend's sustainability in the face of Windstream's debt is quite reasonable (and the many shares shorted reflect plenty of doubt), but it's also reasonable to be hopeful, as Windstream sports positive free cash flow and growth potential.

BioMarin Pharmaceutical is a rare-disease drug specialist with an attractive pipeline. Investors are most interested in its Vimizim drug, which targets Morquio A syndrome (also known as mucopolysaccharidosis IV type A, or MPS IVA), and is getting close to an FDA approval decision (possibly in February), and also in its cancer-fighting PARP inhibitor, BMN673. It has been seen as an acquisition target by many, but my colleague Sean Williams has pointed out that it's not exactly trading at bargain levels these days. Analysts at JPMorgan Chase included BioMarin among the company's top biotech stocks for 2014, citing improving cost control. Orphan drug treatments might not seem like a great business, but they tend to have little to no competition and can command high prices.

Finally, Columbia Wanger's biggest closed positions included Ariad Pharmaceuticals and Deckers Outdoor Corporation.

We should never blindly copy any investor's moves, no matter how talented the investor. But it can be useful to keep an eye on what smart folks are doing. 13F forms can be great places to find intriguing candidates for our portfolios.