(Reuters) - Shares of former U.S. President Donald Trump's media company surged to their highest since June on Monday, extending a recent rally as betting odds favored the Republican candidate in the final stretch of his bid for reelection to the White House.

Shares of Trump Media & Technology Group, which operates the Truth Social app, jumped 20% to $46.93. The stock has nearly quadrupled since sinking to an all-time low in late September.

Since its listing, Trump Media has been popular with traders who view it as a speculative bet on Trump winning the Nov. 5 election. He owns 57% of the company, making his stake now worth over $5 billion.

Trump Media's revenue in the June quarter was $837,000 and the company is burning cash. Strategists say its $9 billion stock market value is detached from its day-to-day business.

With eight days to go before the election, betting odds reflect expectations Trump is likely to beat Vice President Kamala Harris, the Democratic candidate. However, opinion polls show a tight race in the seven battleground states that are expected to determine the winner.

Oddschecker.com, which reflects odds across a number of betting platforms, had Trump at the equivalent of about a 62% chance of winning and Harris at about 38%.

On the PredictIt platform, contracts for a Trump victory traded at 61 cents, with a potential $1 payout. Harris contracts were at 43 cents.

Polymarket has Trump with a 66% chance of winning and Harris at 34%.

Bitcoin added 2.5%, extending recent gains. Trump has positioned himself as pro-cryptocurrency.

Harris was traveling to Michigan on Monday to focus on the economy, while Trump was heading to Georgia to shore up support among religious voters.

(Reporting by Noel Randewich; Editing by David Gregorio)