While the markets are looking better for many investors after the August sell-off, not all companies are part of the resurgence.

Some companies saw serious declines in shareholder prices between Sept. 30 and Oct. 30. The bad news crossed industries and hit some well-known firms.

Following are the 20 companies in the S&P 500 that fared the worst, in reverse order, along with the ticker, the price at the end of September, the price at the end of October, and the percentage decrease.

No. 20 Michael Kors Holdings Ltd.

KORS, $42.24, $38.64, -8.3%

No. 19 Kansas City Southern

KSU, $90.88, $82.76, -8.9%

No. 18 Nordstrom Inc.

JWN, $71.71, $65.21, -9.1%

No. 17 Darden Restaurants Inc.

DRI, $68.54, $61.89, -9.7%

No. 16 Harley-Davidson Inc.

HOG, $54.90, $49.95, -9.9%

No. 15 PVH Corp.

PVH, $101.94, $90.95, -10.8%

No. 14 HCA Holdings Inc.

HCA, $77.36, $68.79, -11.1%

No. 13 Chipotle Mexican Grill Inc.

CMG, $720.25, $640.23, -11.1%

No. 12 YUM! Brands Inc.

YUM, $79.95, $70.91, -11.3%

No. 11 Wal-Mart Stores Inc.

WMT, $64.84, $57.24, -11.7%

No. 10 Akamai Technologies Inc.

AKAM, $69.06, $60.82, -11.9%

No. 9 Stericycle Inc.

SRCL, $139.31, $121.37, -12.9%

No. 8 Southwestern Energy Company

SWN, $12.69, $11.04, -13%

No. 7 NRG Energy Inc.

NRG, $14.85, $12.89, -13.2%

No. 6 Endo International Plc

ENDP, $69.28, $59.99, -13.4%

No. 5 Tenet Healthcare Corporation

THC, $36.92, $31.37, -15%

No. 4 Seagate Technology PLC

STX, $44.80, $38.06, -15%

No. 3 Western Digital Corporation

WDC $79.44, $66.82, -15.9%

No. 2 Quanta Services Inc.

PRW, $24.21, $20.11, -16.9

No. 1 CONSOL Energy Inc.

CNX, DRI, $9.80, $6.66, -32%