Older adults report being more trusting than young adults, and this may be particularly evident in close social relationships. This is beneficial for well-being when trust is reciprocated, but detrimental when trust is exploited. In a repeated trust game, young (n = 35) and older adults (n = 33) invested real money over repeated interactions with trustees of varying social distances (close, neutral, distant) and trustworthiness (trustworthy, untrustworthy). Young and older adults were equally proficient at learning to integrate congruent information so that by the end of the task they were investing most with close trustees who reciprocate often and least with distant trustees who rarely reciprocate. Averaged across time, however, older adults were more likely than young adults to invest with all trustees, with the one exception of close trustees who reciprocate often. In addition, among older adults, higher intelligence was correlated with larger investments with the most trustworthy trustees, and better subjective financial well-being was associated with increased investing in the most untrustworthy trustees. Although both age groups demonstrated a confirmation bias by integrating preexisting beliefs with ongoing behavior in order to determine trustworthiness, this effect was most consistent among the young adults. We discuss the potential danger, particularly for finances, when older adults discount information pertaining to trustworthiness and/or untrustworthiness.