What: Shares of furniture-rental chain Aaron's (NYSE:AAN) plunged more than 20% this morning after its quarterly results and outlook missed Wall Street expectations.

So what: Aaron's shares have risen nicely over the past year on a string of market-topping quarters, but today's wide Q3 profit miss -- EPS of $0.39 vs. the consensus of $0.48 -- coupled with downbeat full-year guidance is forcing analysts to quickly recalibrate their growth estimates. In fact, same-store sales for the quarter slipped 4.1% while its bad debt expense rose significantly, suggesting that Aaron's troubles are part of a broader downturn in the rent-to-own space.

Now what: Management now sees full-year 2015 EPS of $2.02-$2.22, down from its prior view of $2.16-2.36. "Core earnings and EBITDA improved in the third quarter as our cost reductions continued to offset a challenging revenue environment," said CEO John Robinson. "We are confident that future results will reflect the strong growth prospects of Progressive and improved execution across our business." With the stock now off more than 35% from its 52-week highs and trading at a single-digit forward P/E, bargain hunters might even want to use today's plunge to bet on that optimism.