The IPO train continues to thunder noisily down the track. According to Renaissance Capital, so far this year 27 fresh stock issues have been priced, a tally nearly 60% higher than at the same point last year. And 2013 was a tough act to follow, being a banner year both in terms of total issues brought to market and funds raised. Those two figures hit their highest levels since the heady days of the Internet gold rush in 2000.

This week will be more of the same, with a clutch of new IPOs listing on the exchanges. It's going to be a busy few days; let's take a breath and consider four of these issues.

We have to caution, however, that IPO investing carries above-average risk, because initial stock prices can be far from the value the market eventually puts on the company's shares. Of course, this situation provides immense upside potential ... though it also presents the chance of losing a big chunk of an investment.

And with that caveat out of the way, here's a look at the four companies on our radar.

Flexion Therapeutics
So far this year, in terms of sector representation health care has been far and away the winner in the IPO race, with more than twice the number of new stocks coming to market as the runner-up, energy. The debuts of this company and Concert Pharmaceuticals (more on that in a moment) will help widen that lead. Flexion Therapeutics develops long-acting, injectable pain treatments for mussculoskeletal conditions. Chief among these is osteoartritis, a form of degenerative arthritis. Osteoarthritis is the most prevalent type of joint disease, afflicting more than 20 million people in the U.S. alone. So although the company is a niche developer, that niche is rather big. Flexion Therapeutics is slated to list on the Nasdaq this Wednesday under the ticker symbol FLXN. Five million shares will be floated at a price of $12 to $14 apiece. The lead underwriters are BMO Capital Markets and Wells Fargo (WFC -0.68%) Securities.

Concert Pharmaceuticals
This interesting biotech play not only develops its own drugs; it also tweaks existing medications with deuterium to make them more effective and reduce negative side effects. It's already attracted several clients interested in boosting the efficacy of their products: Celgene (CELG), Avanir (NASDAQ: AVNR), and Jazz Pharmaceuticals (JAZZ -0.52%) are collaborating with the company at the moment.Concert's finances aren't as bloody as those of some fellow early-stage biotechs -- the top line nearly doubled in the first nine months of 2013 to just under $22 million, while net loss narrowed sharply to $141,000 from the $13 million in the same period the previous year. Wells Fargo Securities and UBS Investment Bank are the lead underwriters of the IPO. As with Flexion, 5 million shares of the firm will be sold at $12 to $14 per share. The stock should bear the ticker CNCE on the Nasdaq and be listed on Friday.

Installed Building Products
America is a busy builder these days. With new home construction recording notable gains in recent times and that growth set to continue. Installed Building Products says it's the second-largest installer of insulation in new homes in America, which is a good position from which to profit from all that construction. The top line has ballooned recently, coming in at $313 million in the first nine months of 2013 against $210 million in the year-ago period. In contrast to fiscal 2011 and 2012, the company landed in the black for Q1-Q3 2013, posting a profit of $4 million. Funnily enough for a company so tied to the U.S. economy, IBP's market debut is being lead-underwritten by subsidiaries of European lenders, namely Deutsche Bank Securities and UBS. The 9 million shares being sold are scheduled to list on the New York Stock Exchange on Thursday, stamped with the ticker symbol IBP, and priced at $14 to $16 per share.

Talmer Bancorp
In the financials sector, regional banking has been a hot segment over the past few years. Buoyed by strong results, numerous regionals have posted sexy stock price gains of late. Talmer Bancorp is no doubt hoping to capitalize on that trend with its growing presence in the Midwest. Total assets amounted to roughly $4.7 billion as of the end of last September, with $3.7 billion in customer deposits. The company posted a net profit each year from 2010 to 2012, and its bottom line for the first nine months of 2013 indicated that the yearly figure would easily top those three preceding years. Stifel's Keefe, Bruyette & Woods and JPMorgan Chase (JPM -0.15%) unit J.P. Morgan are lead-underwriting Talmer Bancorp to market, with nearly 15.6 million shares going on sale for $12.50 to $14.50 apiece. The stock's debut is scheduled for Wednesday, and it should trade on the Nasdaq under the ticker symbol TLMR.