What happened

Shares of HCA Healthcare (HCA -0.29%) had soared by 14.4% as of 10:56 a.m. ET on Friday. The big jump came after the large hospital operator announced its second-quarter results before the market opened.

HCA reported Q2 revenue of $14.8 billion, up from $14.4 billion in the prior-year period. The company posted net income of nearly $1.2 billion, or $3.90 per diluted share. That was down from earnings of $1.45 billion, or $4.36 per diluted share, in the second quarter of 2021.

However, HCA beat Wall Street's expectations on both the top and bottom lines. The average analyst estimate was for revenue of $14.7 billion and earnings of $3.70 per share.

So what

The healthcare stock's jump underscores just how much investing is an expectations game. HCA's revenue increased only slightly year over year while its earnings fell.

Unsurprisingly, HCA faced some key challenges in the second quarter. The labor market remained tight. Rising inflation pushed the company's costs higher. HCA also had some one-time expenses that weighed on its bottom line, including losses of $32 million on the sales of facilities and $78 million on the retirement of debt.

Same-facility admissions slipped 1.2% year over year in Q2. Same-facility surgeries also declined -- 2.3% for inpatient surgeries and 1.4% for outpatient surgeries. There was some good news, though. HCA's same-facility emergency room visits jumped 7.3%. Its same-facility revenue per equivalent admission rose 3.5%.

Now what

COVID-19 could still be the most important factor for HCA's performance in the next few quarters. If the company's hospitals are inundated with COVID-19 patients, those institutions could be forced to postpone elective surgeries.