mumbai, July 25 -- Retail investors, including high-net-worth individuals, have suffered significant losses this week as the benchmark Nifty 50 slipped below the 24,000 level, which had served as a strong support for weeks. Having correctly anticipated the initial correction, they turned bullish again just as renewed tensions in West Asia sparked a broader sell-off, leaving their index call bets deep in the red. These investors, who tend to be net buyers of Nifty 50 and Nifty Bank call options and net sellers of puts, apart from being bullish on stocks, actually played a negative card for this Tuesday's weekly Nifty expiry. After remaining net long until last Thursday, retail investors turned net sellers of index calls on Friday and Monday, expecting the Nifty to correct. It did, allowing them to pocket gains. A call seller, or bear, gains when the underlying index or stock falls or remains flat. A put seller, or bull, gains when the opposite happens. Call buyers are bullish, while put buyers are bearish. However, they have turned net bullish on index options again since Tuesday, expecting the 24,000 support level to hold despite the resumption of fighting in West Asia, weeks after a fragile ceasefire signed by the US and Iran on 17 June came apart. But the fall in the markets, with the 24,000 call expiring on 28 July (coming Tuesday), since they again became buyers, has burnt their fingers. The 24,000 call has fallen almost 80% to Rs.75 per share-65 shares make one contract-on Thursday, down from Rs.343 on Monday. The cohorts turned long index calls on by 146,775 contracts on Tuesday, showed data from the National Stock Exchange. This after turning net short index calls by 211,750 contracts on Friday and 104,565 on Monday. The sellers on index calls tend to be foreign portfolio investors, according to NSE data. "The steep fall in calls has trapped the buyers, thanks to a surge in geopolitical tensions," said Kruti Shah, quant analyst at Equirus Securities. The tensions, which began building since 10 July, saw Brent crude surge 31% to $100.69 a barrel since that date through Thursday, according to investing.com. For India, world's third-largest importer of crude, the rise in oil prices since the start of the war end February threatens its macroeconomic outlook....