Wednesday was a down day for the stock market, as investors once again tried to put major news into a longer-term context. The Federal Reserve's Open Market Committee voted to raise short-term interest rates by a quarter percentage point as expected, and it adopted a generally hawkish tone that suggests that future rate increases could come slightly more quickly than most of those watching the central bank had expected. That news didn't result in big moves for major benchmarks, but it did affect certain sectors of the market. Moreover, some individual companies had investors particularly nervous about their future prospects. J.C. Penney (JCPN.Q), KB Home (KBH 0.14%), and Boston Scientific (BSX 0.55%) were among the worst performers on the day. Here's why they did so poorly.

Penney for your thoughts

Shares of J.C. Penney fell almost 8% as the retailer continued to struggle through difficult financial conditions. Many investors have grown increasingly nervous about J.C. Penney's prospects, especially as some of its department-store retail rivals have shown more impressive rebounds for key business fundamentals recently. Moreover, the departure of former CEO Marvin Ellison suggested that J.C. Penney might have little choice but to seek a different strategic direction in light of its sluggishness lately. Recent margin pressure and sales challenges show few signs of letting up. Without a fast turnaround, J.C. Penney will have trouble reversing its downward trend.

Person picking up packages from clerk behind counter with sign reading JCP.com Order Pickup.

Image source: J.C. Penney.

KB Home investors fear rate hikes

KB Home stock dropped 7% on a relatively poor day for several players in the homebuilding industry. Today's move from the Federal Reserve not only pushed short-term rates immediately higher but also pointed to the likelihood of a higher terminal rate for this upward cycle in interest rates. If longer-term rates follow suit, then that would translate into higher financing costs for mortgage borrowers, potentially reducing demand for homes. KB Home benefited greatly in 2017 from the lack of supply of entry-level homes, seeing its stock double in price. Yet given that entry-level buyers are the ones most likely to get priced out on the margin by a rise in interest rates, KB Home potentially has more to lose from adverse rate moves.

Boston Scientific might not get bought out after all

Finally, shares of Boston Scientific sank 6%. The medical device maker had jumped earlier in the week on reports that it might receive a takeover bid from industry peer Stryker (SYK 0.66%). Yet today, Stryker denied that it had been in acquisition talks with Boston Scientific, throwing cold water on the idea. With the downward push, Boston Scientific is now back to where the stock started the week before the reports surfaced in the first place. Boston Scientific will now apparently have to make the most of its own opportunities in the medical device space -- at least unless another potential buyer comes around.