By Noel Randewich

(Reuters) - Shares of Trump Media & Technology Group, majority-owned by former U.S. President Donald Trump, jumped nearly 5% on Monday after a poll showed the Republican candidate is in a tight race against Vice President Kamala Harris for the White House.

The bounce in the company's stock follows weeks of declines that sent it to record lows, and it comes ahead of key dates this month when Trump and other company insiders will be allowed to sell their shares.

Trump Media, whose main asset is the Truth Social app, saw its value balloon to nearly $10 billion following its stock market listing in March, lifted in part by Trump supporters and traders betting he would win the November election.

Monday's rebound in Trump Media follows a new poll suggesting recent gains by Democratic rival Harris against Trump have stalled and potentially reversed.

Trump is up one percentage point against Harris at 48%-47%, according to a national poll conducted by The New York Times and Siena College.

With eight weeks left ahead of the Nov. 5 presidential election, contracts for Trump and Harris victories are both trading at 52 cents, with a potential $1 payout, on the PredictIt politics betting platform. Harris had led Trump at 54 cents vs 50 cents as recently as Saturday.

Monday's stock gain in Trump Media follows several weeks of declines and leaves the company's market value at $3.6 billion. That puts Trump's 57% stake at over $2 billion.

For the June quarter, Trump Media reported a loss of $16.4 million and revenue of $837,000 -- equivalent to the sales of two Starbucks stores.

According to provisions related to Trump Media's listing, Trump and other insiders will be allowed to sell stock beginning later this month, potentially flooding the market with additional shares.

If the stock price remains at or above $12 for any 20 trading days commencing Aug. 22, then Trump will be free to sell shares beginning on Sept. 20. Otherwise, he is eligible to sell shares beginning on Sept. 26. The stock was last at $17.94 on Monday.

(Reporting by Noel Randewich; Editing by Leslie Adler)