Wall Street suffered a setback on Wednesday, as pessimism related to goings-on in Turkey cascaded across the emerging-market space and threatened the long rally in the U.S. and other major international stock markets. The Dow Jones Industrial Average dropped more than 100 points, declining from near-record levels, and other benchmarks lost up to 1.2%. In addition to the general malaise, some stocks fell on company-specific issues that worried investors. J.C. Penney (NYSE:JCP), Diamondback Energy (NASDAQ:FANG), and Micron Technology (NASDAQ:MU) were among the worst performers on the day. Here's why they did so poorly.

J.C. Penney braces for impact

Shares of J.C. Penney dropped 9% on a poor day for the retail industry. The company is scheduled to release its latest earnings report tomorrow, but declines for department store peer Macy's stock foreshadowed possible headwinds when those results come out. Investors have been desperate to see any signs of a turnaround for J.C. Penney, and some believe that the department store chain is making a smart strategic move to emphasize children's apparel following the liquidation of the Babies R Us store network. Nevertheless, with the company having executed poorly on so many promising opportunities in the recent past, today's drop shows how hard it is to get J.C. Penney investors excited about the positives that the future could bring.

Shopper at J.C. Penney order pickup desk with two packages from the sales clerk.

Image source: J.C. Penney.

Diamondback gets bitten

Diamondback Energy stock lost 12% after the energy company agreed to buy fellow shale-energy player Energen (NYSE:EGN) in a deal worth $9.2 billion. Under the terms of the proposed acquisition, Diamondback will give Energen investors 0.6442 shares of Diamondback stock for every share of Energen they own, putting a value of nearly $85 per share on the transaction based on Monday's closing price for Diamondback. Proponents of the deal point to the two companies' complementary positions in the promising Permian Basin region, but skeptics are nervous that the move could result in slowing growth and fail to produce the synergy-related gains that Diamondback currently expects.

Micron could see tougher times ahead

Finally, shares of Micron Technology fell 6%. Analysts at Wells Fargo cut their price target on the memory-chip maker from $70 per share to $63, citing reduced expectations for capacity and pricing strength on both traditional DRAM chips and NAND flash memory products. The analysts kept an outperform rating on the stock, but nervousness about how long the strong part of the memory-chip cycle can last after a sizable upward move already has some shareholders choosing to take their profits off the table. With potential exposure to any downturn in chip demand, it's easy to see why some investors wouldn't necessarily want to bank on Micron holding onto its recent gains.

Dan Caplinger has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.