Indian shares are set for a weak October. Brokerages say foreign investors have ramped up short positions after September’s derivatives expiry signalled a risk-off turn.

The Nifty 50 fell 6.7 percent during the September derivatives series. That made it the worst performer among Asian markets. Bank Nifty declined 5.7 percent and contributed the most to benchmark losses.

Foreign investors’ net index-futures shorts rose to about 267,000 contracts from 184,000 at the previous expiry, Nuvama data showed. They sold 2.7 billion dollars of Indian shares in the spot market, a six-month high.

IIFL Capital sees scope for a technical rebound toward 23,300. But it warns that a sustained break below 22,400 could open the door to more losses. Nuvama sees the benchmark between 22,350 support and 23,400 resistance.

Nearly half of futures and options stocks ended September with long positions unwound. More than 40 percent saw a buildup of shorts, Ambit Capital said.

On October 1, the Sensex closed at 71,909.70, down 570 points. The Nifty ended at 22,421.95. The benchmarks have closed in the red for eight straight weeks. Trading resumes on October 5 after the October 2 holiday.