The hottest new Silicon Valley IPO may just be the San Francisco 49ers: As fans pick up stock in the team by purchasing seats in the new Santa Clara stadium, they could sell the seats in the future at either huge profits or steep losses depending largely on how the team plays.

Niners fans last week began paying one-time costs of at least $2,000 to buy each of the 50,000-plus seats in the stadium, giving them the right to season tickets beginning with the Santa Clara kickoff in 2014. But fans can later sell their seat “license” to fellow 49ers enthusiasts, like a stock. Already, some speculators are gobbling up seats, planning to wait for their value to rise so they can profit in coming years.

A review by this newspaper of other NFL teams shows that Pittsburgh Steelers fans, for example, have resold their seat licenses for up to 17 times what they paid originally by taking advantage of low initial prices and their teams’ success on the field. But even buyers in big markets with die-hard fan bases like the Dallas Cowboys have lost more than $10,000 per seat after paying too much at the start and selling during losing streaks.

Those who buy high-priced seats in the Santa Clara stadium now, at the peak of Niners fever, may wind up like investors who last month bought stock in the super-hyped Facebook IPO, before shares famously plummeted.

“I think they’re going to have a tough time making an easy buck buying when the market is high,” said Greg Carl, managing partner with PSL Source, a North Carolina firm that brokers seat license sales. “I would not anticipate it shooting up out of the gate.”

Fans of other NFL teams have made their profits the same way investors do on Wall Street: buy low, sell high.

Take the Carolina Panthers. The team came into the NFL in 1995 and struggled to win, but the value of the seats tripled by the time they made the Super Bowl in 2004. Then by 2010 they were the worst team in the league, and seat licenses were selling at below their original price. It proved to be a good time to buy, as the emergence of young star quarterback Cam Newton last year helped prices creep up again.

“It is an asset, and we make sure we explain that to people, that it can go up and down in value,” said Al Guido, who is leading the 49ers’ sales effort.

There are more than a dozen NFL teams that sell seat licenses, which help fund new stadiums like the 49ers’ $1.2 billion home field under construction next to Great America.

Niners fans have to foot a one-time bill of $2,000 to $80,000 to buy seats, and can finance the cost over 10 years. On top of that, they must pay $850 to $3,750 each year for season tickets. If a fan can’t afford to buy season tickets any more, moves away or loses interest in the team, they must sell their seat license to another fan.

The high prices compare only to the two newest NFL home fields: the New York Giants’ and Jets’ MetLife Stadium and Cowboys Stadium.

With the vaunted Cowboys struggling on the field more than two years after their new stadium opened, 90 percent of the seats are reselling for less than what fans originally paid for them. Forty percent are more than half-off the initial price, Carl said. But he cautioned that things could turn around, particularly if the mediocre Cowboys start playing better.

Most resale seat prices for the Super Bowl-champion New York Giants, meanwhile, have increased about $500 on average in the two years since MetLife Stadium opened, according to data from the team’s broker, STR Marketplace. The high-priced club section seats, however, have declined about $3,000 per seat.

Most famously in the Bay Area, the Oakland Raiders’ seat licenses that went on sale in the mid-1990s essentially became worthless after the team couldn’t sell out games, allowing fans to buy individual game tickets at face value at the box office without having to pay the seat costs.

“Oakland did everything wrong. The pricing was wrong, the team was bad and they had an expiration date on them,” which caused the license to lose value every year, said Neil deMause, a New York-based author and stadium critic.

Seat licenses for the 49ers and other teams don’t expire, as long as fans keep buying season tickets, making them uneven comparisons to the Raiders’ failure.

Seat licenses increased an average of 18 percent each year over the past decade at the nine stadiums that opened in the late 1990s and early 2000s, said sports business consultant Brian Connolly, who founded Dallas-based Victus Advisors. In the most drastic example, the seat value soared a total of 1,600 percent in the past decade for nosebleed seats for the Steelers, a perennial power with a die-hard fan base.

“History has shown in the NFL that these do rise in value, it’s just a matter of how much,” said Connolly, who called the purchase of 49ers seats a sound investment. “It’s simple economics: You’re purchasing the right to a seat and there’s a limited supply of those licenses.”

Yet other experts say the old growth rates are likely a thing of the past simply because prices in the latest wave of stadiums like the 49ers’ are so much higher that there’s little room to grow.

Consider this: Niners seat prices are already so high that for them to surge in value at the same rate as the Steelers’, the most expensive seats would hit an astronomical $1.4 million each a decade from now. Put another way, if already pricey Apple stock increased at that same rate, it would skyrocket toward an absurd $10,000 a share.

While the whole point of playing the stock market is to make money, many fans just want to enjoy the games and have no intention of selling their seats. In fact, the 49ers and other teams could face the wrath of the Securities and Exchange Commission if they advertise the seats as an “investment,” and the Niners require buyers to sign a contract stating they have “no expectation of profit.”

“But if they do want to sell it,” the 49ers’ Guido said, “and they turn out to make money on it, they absolutely can.”

Contact Mike Rosenberg at 408-920-5705. Follow him at Twitter.com/rosenberg17.