2015 was honestly kind of a dull year if you were waiting for big IPO action. Only 169 companies decided to go public that year - basically half the number we saw in 2014. The money flowing into these debuts dried up too, with IPO funding dropping from $85 billion down to just $30 billion. Market sentiment had cooled off pretty hard, and even the mega-hyped private companies like Uber just kept raising cash without bothering with a public listing.

But among the companies that actually did make the jump to public markets, there were some wild swings. Worth looking at how the 2015 IPO class actually performed.

On the winner side, Spark Therapeutics came out swinging. They went public in January focused on gene therapy for rare eye diseases, priced their shares at $23 after originally planning for $19-21, and by December they'd climbed 122%. Positive clinical trial results in October gave them another leg up.

Seres Therapeutics was another biotech success story from that cohort. They hit the market at $18 in summer and more than doubled from there - up 106% by year end. Still burning cash like most early-stage biotech companies do, but they had runway through at least mid-2017.

Shake Shack also made the list of best performers from that year's IPO batch. The New York burger joint priced at $21 in January and more than doubled. They peaked at $96.75 in May before pulling back, but even after giving back some gains, shareholders were sitting on over 100% returns.

Then there were the disasters. MaxPoint Interactive launched at $11.50 in March and got absolutely hammered, losing 88% of its value. Their digital marketing tech was actually driving sales growth - up 33% in one quarter - but investors got spooked by mounting losses. Growing your customer base means nothing if you can't do it profitably.

Zosano Pharma had an even rougher ride. Their microneedle patch technology looked promising at the $11 IPO price, but things fell apart in September when they ditched their osteoporosis program and ended a partnership with a major pharma company. The stock shed 77% of its value.

Belloran Pharmaceuticals rounded out the disaster list from that year's batch of companies that had their IPO in 2015. Another biotech that excited investors initially with its pulmonary hypertension treatment, only to crater and lose about 75% by year end.

Honestly, biotech companies tend to dominate both ends of the IPO performance spectrum - huge winners and massive losers. 2015's list of companies that had their IPO showed exactly that pattern. You always get winners and losers in any IPO class, but investors were hoping for more balanced action in 2016.