The Asset and Health Dynamics Among the Oldest Old (AHEAD) study shows a large increase in reported total wealth between 1993 and 1995. Such an increase is not found in other US household surveys around that period. This paper examines one source of this difference. The authors find that in AHEAD 1993 ownership rates of stocks, CDs, bonds, and checking and saving accounts were under-reported, resulting in under-measurement of wealth in 1993, and a substantial increase in wealth from 1993 to 1995. The explanation for the under-reporting is a combination of question sequence and wording in the AHEAD survey instrument.