Buying shares in a public company used to be straightforward and simple. Buyers instructed their broker to trade shares with the simple maxim: “buy low, sell high.”

These days, things are more complicated thanks to wealthy investment banks that have created Wall Street’s version of a Las Vegas casino. Today, buyers don’t even need to purchase shares in a company — they can make a killing just by betting at sites like suomikasinot.fi whether they believe a share price will increase or decrease.

The Options Regulatory Surveillance Authority is now investigating a sudden surge in such option trading just before AT&T launched its $1.19 billion cash bid for Leap Wireless, owner of the Cricket-branded prepaid cell service.

The unnamed buyers included investment bank Goldman Sachs, that either traded options for themselves, on behalf of well-heeled clients, or simply processed the trades as part of doing business.

Those who purchased the call options were either clairvoyant, extremely lucky, or had inside knowledge of the yet-to-be-announced deal and were able to buy thousands of lucrative contracts that bet Leap stock would make a sudden recovery and increase in price. Nanex reports an explosive increase of 15,749 Leap “call contracts” trading hands that week, according to a report in USA Today. That well-surpassed that same week’s 1,384 Leap “put contracts” — investors making the safer bet that the always-anemic Leap stock would fall in price even further. That particular week, they were very wrong.

During the last 15 minutes of trading on July 12, 2,536 Leap contracts were executed, and nearly 80 percent of them gave buyers the right to purchase Leap shares for $9 each through Aug. 16, an amazing display of confidence in a stock that traded as low as $6.58 per share a few weeks earlier.

Leap into the big money pool.

Other investors were left scratching their heads over the wisdom of that kind of trading until just after the market closed that day, when AT&T announced its intention to buy the prepaid carrier, boosting Leap’s stock price from $7.98 on July 12 to $17.23 on Monday, July 15.

“Did someone know something early in Leap Wireless?” asked Jon Najarian, co-founder of Option Monster, a provider of options-trading ideas, in a written commentary for TheStreet.com. “The question now is whether someone will end up in prison for insider trading.”

While the unnamed parties likely made a handsome and quick profit, the brokerages that sold the options took a beating.

“We, as market makers … sold these calls,” said Thomas Peterffy, head of Timber Hill and an affiliated group of brokerages. “When the news came out, we had an immediate loss of $1.5 million.”

Goldman $achs

Timber Hill promptly filed a request for an investigation into potential illegal insider trading with the Options Regulatory Surveillance Authority that has since responded it was reviewing the issue “to determine if any exchange or Securities and Exchange Commission rules may have been violated.”

A Nasdaq spokesperson did not respond to messages seeking comment. Goldman Sachs also declined to comment.

Peterffy told the newspaper securities regulators should pursue examples such as the Leap Wireless options trading, “where it’s very clear what happens.”

“This has been going on for 20 years. It happens all the time, happens about 20-30 times a year. And we’ve never seen a penny from this stuff,” said Peterffy.