What: Shares of United Rentals (NYSE:URI) dropped as much as 17% in early trading Thursday after reporting earnings. As of noon ET, the stock was down 15%.

So what: Fourth-quarter revenue fell 3% to $1.52 billion and net income dropped 13% to $169 million, or $1.81 per share. Revenue was only slightly below the $1.53 billion Wall Street analysts expected, but they were guessing earnings would be $2.31 per share and that's what has investors worried today.  

Management also gave 2016 guidance of $5.65 billion to $5.95 billion in revenue, where the midpoint is below 2015's revenue of $5.82 billion.

Now what: While the market may not like United Rentals' earnings trend, I can't help but see incredible value in the stock. Shares trade at just 7.7 times earnings and expected free cash flow of $900 million to $1.0 billion is attractive when compared to the $4.4 billion market cap. Management has a $1 billion share buyback program in place and that could help drive earnings per share higher. Though the business may not be in growth mode, it has a solid competitive moat and great value for investors getting in today.