KARACHI (Bloomberg) — Pakistan investors stormed out of the Karachi Stock Exchange, smashed windows and cursed regulators after the benchmark index fell for a 15th day, the worst losing streak in at least 18 years.

"I have lost my life savings in the last 15 days and no one in the government or regulators came to help us," said Imran Inayat, 45, a protester and a former banker who retired early and said he lost 300,000 rupees ($4,175) on the market.

Police surrounded the exchange after hundreds of investors stoned the building and shouted anti-government slogans. They directed their ire at the government and Securities and Exchange Commission of Pakistan, which this week removed a one-percent daily limit on price declines. The measure was aimed at halting a slide that wiped out $30 billion of Pakistan's market value in three months, threatening to undo a 14-fold rally since 2001.

"There has been some level of mismanagement by the authorities," said Habib-ur-Rehman, who manages the equivalent of 6.5 billion rupees in Pakistani stocks and bonds at Atlas Asset Management Ltd. in Karachi. "This may be due to their misperception that they can prevent the market from falling. Investors have to learn to bear losses as they do gains."

The benchmark Karachi Stock Exchange 100 Index dropped 278.96, or 2.7 percent, to 10,212.92 at the close. The index has plunged 35 percent from the record of 15,676.34 on April 18.

Regulators this week eased the curbs on trading after volumes fell to the lowest in a decade. The restrictions, including a ban on short-selling, were lifted with effect from July 14 by the securities commission after the exchange announced a 50 billion rupee fund to buy stocks. Short sellers borrow shares and sell them, hoping to replace the stock at a lower price and pocket the difference.

"We demand that all stock prices be frozen at current levels," said Kauser Javed, who heads the Small Investors Association.

"People have sold their assets in the last 15 days to meet payments and if things continue this way, you will start hearing of suicides."