NEW YORK (TheStreet) -- Etsy  (ETSY), the Brooklyn-based online marketplace, debuted on the New York Stock Exchange on Thursday at $31 a share, nearly double its initial public offering price of $16 a share.

The stock reached a peak of $35.74, more than double the IPO price, shortly after it began trading, but quickly sold off down into the $30 range.

The company, which sells handmade goods, has yet to post a profit, but it claims to have more than one million active sellers and 19.8 million active buyers on its site. Etsy also said it has achieved almost $2 billion in gross sales last year with buyers or sellers in nearly every country.

Time will tell how Etsy fares on the market. Will it be a quick flash in the pan that fades away shortly after the initial hype? Or will it have staying power and continue to move higher?

The conditions don't seem too nurturing, as the IPO market slowed significantly in the first quarter of 2015 after a record year in 2014. The 34 IPOs in the first three months of the year raised $5.4 billion, which marks the least active quarter by IPO count since the first quarter 2013 and the smallest by proceeds raised since the third quarter 2011.

The health care sector remained active thanks to biotechs, and the sector accounted for half of all IPOs in the period.

Household names such as Box  (BOX), GoDaddy  (GDDY), and Shake Shack  (SHAK) went public, but technology, consumer, and energy IPOs dropped below their historical averages. 

With all of this in mind, let's take a look at the top five best IPO performers in the last 12 months. These are the companies that have generated the highest return percentages since their debuts.

5) Spark Therapeutics (ONCE - Get Report)

Offer Date: 1/29/15
Underwriter: JP Morgan
Industry: Health Care
Deal Size: $161 million
Offer Price: $23
First Day Close: $50
Closing Price (4/15/15): $76.14
First Day Return: 117.4%
Total Return: 231%

4) Kite Pharma (KITE)

Offer Date: 6/19/14
Underwriter: Jefferies
Industry: Health Care
Deal Size: $128 million
Offer Price: $17
First Day Close: $29
Closing Price (4/15/15): $64.08
First Day Return: 70.6%
Total Return: 276.9%

Jared Dillian commented on Kite Pharma in a recent post on Real Money. Here is what Dillian had to say about the stock:

I own Kite Pharmaceuticals, which is also working on a cure. There is a bit of a cancer cure arms race going on, which is great.

So anyway -- back to the earlier question -- is biotech a bubble or not? The answer is, pretty obviously, no. How can you get cynical about a cure for cancer?

Admittedly, valuations in biotech have gotten pretty stretched (at least in small-cap land) and people are just raising unbelievable gobs of money, and there is some excess. But we are also living in an age where we are at the cusp of many incredible medical advances. From a business standpoint, there are advances that people have virtually no choice but to pay for. No government, no insurance company is going to deny people a cure for cancer. And if you come up with a cure for cancer, you deserve to get pretty rich. And there are 300 different kinds of cancer, all requiring different treatments.

Biotech and health care could be in a bull market for many years.

From a short-term trading standpoint, it looks like biotech is in correction/consolidation mode. That is fine. And for sure, the easy money has been made, by the smart guys. I'm OK with being a dumb guy and trading the trend, which I think will persist for years to come.

- Jared Dillian, 'Is Biotech a Bubble?' originally published 3/31/2015 on Real Money

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3) CyberArk Software  (CYBR - Get Report)

Offer Date: 9/23/14
Underwriter: JP Morgan
Industry: Technology
Deal Size: $86 million
Offer Price: $16
First Day Close: $29.93
Closing Price (4/15/15): $61.66
First Day Return: 87.1%
Total Return: 285.4%

James "Rev Shark" Deporre commented on CyberArk in a recent story on Real Money. Here is what Deporre had to say about the stock:

We have a mood shift this morning, as buyers have decided to stop chasing a low-volume walkup. The lack of vigor behind the recent move has sapped confidence, but the consistency of the buying has helped to keep the bears on defense. This morning Greece provided some headwinds and oil lost some of its recent momentum, which seems to be enough to create pressure.

Breadth is running 1,950 gainers to 3,100 decliners, but most notable is the lack of strong sector leadership. Netflix (NFLX) and Panera (PNRA) are attracting all the momentum interest, while few other pockets of momentum are active. One group of interest is network and computer security, as CyberArk, Tableau Software (DATA), Vasco Data Security International (VDSI) and a few others in that group act better.

Twitter (TWTR) is exhibiting a little relative strength, and I've remounted some shares as it looks like support around $50 is solid. I continue to like the way Tower Semiconductor  (TSEM) is setting up and we have interesting technical action in solar energy names like SunPower (SPWR).

The dip buyers are starting to show interest as the bears scoop up pennies and give up again. This market is not going to roll over easily.

- James "Rev Shark" Deporre, 'Where's The Dumb Money?' originally published 4/16/2015 on Real Money

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2) Atara Biotherapeutics (ATRA)

Offer Date: 10/15/14
Underwriter: Goldman Sachs
Industry: Health Care
Deal Size: $55 million
Offer Price: $11
First Day Close: $10.65
Closing Price (4/15/15): $47.75
First Day Return: -3.2%
Total Return: 334.1%

1) Radius Health (RDUS - Get Report)

Offer Date: 6/5/14
Underwriter: Jefferies
Industry: Health Care
Deal Size: $52 million
Offer Price: $8
First Day Close: $8.01
Closing Price (4/15/15): $41.58
First Day Return: 0.1%
Total Return: 419.8%