This article studies the relationship between credit provision and stock trading behavior. We collect every stock transaction of the three major British companies during the 1720 South Sea Bubble and link stock trading to margin loan positions with the Bank of England. We give insights in the selection of traders into the loan facility by comparing the trading behavior and realized returns of borrowers to other traders. We find that loan holders are more likely to buy following high returns and document strong underperformance of borrowers.