Source: Shake Shack.

Shake Shack (SHAK -2.87%) may be known for its frozen custard concretes, but it's been drying cement for shareholders that have seen the stock shed more than half of its value since its springtime peak.

The fast-growing burger chain is still trading well above January's IPO price of $21, but things have been volatile for the chain that went on to more than quadruple by the time its stock peaked at $96.75 in May. It actually hit a new low this week. We went over some of Shake Shack's best headlines of 2015 a week ago. Now it's time to go over some of the stories that didn't break the chain's way this year. 

Jan. 29: The IPO prices
Shake Shack was initially hoping to price its IPO for as little as $14. Demand was strong enough to bump that to $21, but that still was no match for the retail investor hype. The stock opened at $47, and it didn't look back for the first few months. This was a great time for Shake Shack, but it also birthed the volatility and momentum that eventually cut both ways. The stock had a great run through May, but now it's trading for less than its initial open on Jan. 30. 

July 7: Chicken little
Shake Shack introduced the ChickenShack sandwich over the summer. This would naturally be a great event. The "better burger" chain taking the logical evolutionary step to add a premium poultry offering to go with its flagship burger is what the larger burger flippers have done. However, this was a bit of a letdown to the market since its stock peaked in late May on news that it had taken out a ChickenShack trademark. Some bulls were speculating that it would be rolling out a sister concept specializing in fried chicken, and not just a menu addition to its existing offerings. 

This was also the day that Morgan Stanley downgraded the stock. This is notable, because Morgan Stanley was one of the companies that managed the IPO just six months earlier. It also slapped a $38 price target on the stock. There were others including Bespoke Investment Group and Mad Money's Jim Cramer talking down Shake Shack's near-term prospects on valuation concerns in the weeks leading up to the Morgan Stanley dis, but this was still a huge downgrade given Morgan Stanley's role in taking the eatery public.

Aug. 12: Secondary offerings are primary concerns
Shake Shack priced a secondary offering of 4 million shares at $60 apiece. It wasn't a dilutive transaction. That's the good news. The bad news is that it's not dilutive because all of the stock came from existing investors. This was always a concern when Shake Shack went public at $21, popping out of the gate. Early investors wanted to cash out, and the end result is more shares in the previously razor-thin float.

Nov. 30: Short stack
Short interest hit a high of 4.1 million shares by the end of last month. This is not a large number, but it is relative to Shake Shack's modest float. More importantly, we've seen interest consistently inch higher through the second half of the year. Exchanges report short interest twice a month, and we've seen the number of Shake Shack shares sold short increase for 11 periods in a row. 

Shake Shack's uptick in short interest came despite posting another blowout quarter two weeks earlier where comps clocked in with a beefy 17.1% year-over-year increase. Skepticism is growing on Shake Shack heading into 2016, but we can also say that the stock has never traded this cheap by nearly every popular metric.