The assessment is based on multiple high-authority sources that directly confirm the statement. A MarketWatch overview explicitly reports a '562-point rally' in a recent trading session, which surpasses the 500-point gain mentioned in the statement. This provides direct, contemporary evidence. Furthermore, a definitional article from The Economic Times provides a verifiable historical fact: the largest one-day gain for the Dow Jones was 1,086.25 points. This historical precedent firmly establishes that a 500-point gain is not only possible but has been significantly exceeded in the past. Other authoritative sources, such as Investing.com and CME Group, confirm that this type of daily market data is meticulously tracked and reported. While one source from Barron's noted a daily loss, this does not contradict the statement, as the claim refers to 'a specific trading session,' not every session. Several other sources were deemed irrelevant as they pertained to different financial indices or individual stocks. The convergence of direct, recent, and historical evidence from credible financial news outlets makes the statement highly credible.