We examine how the rd,~ionship between bank ownership structure and risk-raking may be differently affected by the different regulatory regimes in the U.S. banking industry. We find that higher insider-ownership banks had greater risk-raking incentives than lower insider-ownership banks between 1987-1990 (a period of relative deregulation and decline of the U.S. banking industry), when we represent risk-raking by systematic risk. However, chis greater systematic risk-caking is unprofitable, indicating chat banks pursued perverse risky strategies in the lace l 980s as suggested by the moral-hazard hypothesis in banking literature. Bue we find char greater systematic risk-caking incentives of higher insider-ownership banks than lower insider-ownership banks disappeared, and that the association between risk-raking and profitability improved over the period of tightened regulation (1991-1995). These results may offer some supp:ming evidence for the effectiveness of regulatory reforms in the U.S. banking industry beginning around 1991. In testing the partitioned sample between lower insider-ownership banks vs. higher ones, we find that the positive relationship between insider ownership and risk-raking, and the negative relationship between the risk-taking and profitability, is significantly more transparent JOY the set of hankJ with lower insider mi11ership over the period 1987-1990. Thus, at r'flJ' lrn11 /weir of stock ownership, banks greatly increase risk, but ultimately unprofirahle risks, as the level of imider ownership rises over the period of dc:regulation and decline of the banking industry. This result is consistent with the corporate-control hypothesis. Over the periOO 1 lJ) 1-1995, we also find char at high levels of stock ownership, banks sc:c:med to engage in profirable risk-taking as the level of insider ownership rose, as predicted by the corporatc:-control hypothesis. Overall, in terms of only addressing the owner/manager agency problem, these results strongly suggest that in years of deregulation, the owner/manager agency problem of banks can be easily addressed by changing insider holdint,rs or ownership structure ro accommodate increased risk. But this policy suggestion should be taken with caution, since banks seem to take on more than enough risk in years of deregulation, which may ultimately increase the probability of bank failure. TI1is might suggest that the increase in insider holdinb:rs to address the ov,rner/manager agency problem should be associated with closer monitoring of the banks' risk-taking behavior. This policy suggestion shoulJ he encouraged more strongly, especially to banks with very low levels of stock ownership.