The New York Times and outside experts tallied enforcement activity at the S.E.C. and the Justice Department, the two most powerful agencies policing the corporate and financial sectors. Comparing cases filed during the first 20 months of the Trump presidency with the final 20 months of the Obama administration, the review found:

• A 62 percent drop in penalties imposed and illicit profits ordered returned by the S.E.C., to $1.9 billion under the Trump administration from $5 billion under the Obama administration;

• A 72 percent decline in corporate penalties from the Justice Department’s criminal prosecutions, to $3.93 billion from $14.15 billion, and a similar percent drop in civil penalties against financial institutions, to $7.4 billion;

• A lighter touch toward the banking industry, with the S.E.C. ordering banks to pay $1.7 billion during the Obama period, nearly four times as much as in the Trump era, and Mr. Trump’s Justice Department bringing 17 such cases, compared with 71.