Available data on prediction and betting markets in early–mid October 2020 shows Joe Biden was indeed trading in roughly the 60–70% implied probability range that Sacks described. For example, a Forbes piece on October 7, 2020 reported prediction market PredictIt giving Biden a 65% chance of victory, and noted this was an increase from the previous week. (forbes.com) Another Forbes article on November 2, 2020 stated that PredictIt had Biden “near-70% highs earlier this month,” indicating Biden’s odds had recently been around the 70% level in October. (forbes.com) A Smarkets exchange update on October 21, 2020 reported Biden at a 63% chance at that time and noted his lead had recently reached 71% versus Trump’s 29%, again consistent with the 60–70% range Sacks referenced. (prnewswire.com)

Sacks’s claim, normalized as “As of early October 2020, Joe Biden has roughly a 70% probability of winning, in line with betting market odds,” therefore matches independent reporting on those markets at that time. In addition, Biden did go on to win the 2020 U.S. presidential election, securing 306 electoral votes to Trump’s 232 and being inaugurated as the 46th president on January 20, 2021. (cnbc.com) Taken together, his characterization of the odds was accurate relative to contemporaneous markets, and the higher-probability outcome he pointed to (a Biden win) is what actually occurred, so this prediction is best classified as right.