What: Shares of SeaWorld Entertainment (SEAS) fell 14.6% in the month of June. Though SeaWorld is trading well above its 52-week low of around $15 per share set this past December, shares of the theme-park operator have still fallen by roughly a third over the past year and badly underperformed the broader market.

SEAS Chart

SEAS data by YCharts

So what: For perspective, SeaWorld still hasn't recovered from its massive 30%-plus single-day drop around this time last year when quarterly earnings badly missed expectations. To its credit, at the beginning of last month SeaWorld also capped a nearly 40% rally from its December lows, driven largely by a surprise 5.6% year-over-year gain in attendance in this year's first quarter. But as fellow Fool Rick Munarriz pointed out at the time, investors still had several reasons to be concerned despite that growth, including the fact the first quarter is seasonally insignificant and that this year's earlier Easter holiday inflated results. In addition, once guests were through the door, they paid an average of 5.6% less in admissions and 1.7% less in food, merchandise, and other in-park costs than during the same year-ago period.

Add to that the waning excitement and subsequent uncertainty of having a new CEO take the reins in April, and it's hard to blame SeaWorld investors for taking some of their recent gains off the table.

Now what: SeaWorld is all set to announce second-quarter 2015 results on Thursday, Aug. 6, 2015. When that happens, analysts expect the company to reveal a 1.7% decline in revenue to $398.3 million, and a 7% drop in earnings per share to $0.40. SeaWorld, for its part, hasn't provided specific guidance for revenue and earnings, but did tell investors last quarter to expect full-year adjusted earnings before interest, taxes, depreciation, and amortization in the range of flat to up 3% versus 2014.

In any case, you can bet the market will be watching closely to see whether SeaWorld meets Wall Street's expectations or revises its own guidance as summer attendance picks up. Either way -- and for better or worse -- I won't be the least bit surprised if SeaWorld investors are forced to endure more turbulence over the next month.