Shares of bank and credit card stocks, such as American Express (NYSE: AXP), Synchrony Financial (NYSE: SYF), and Huntington Bancshares (NASDAQ: HBAN), rocketed higher on Wednesday, up 6.3%, 17.8%, and 11.8%, respectively, as of 11:49 p.m.

The banking sector was broadly lifted after last night's election of Donald Trump and a potential Republican sweep of Congress. The across-the-board rally for financial stocks appears to be due to enthusiasm over the prospect of greater financial deregulation, with perceived "riskier" financial stocks rallying the most.

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Massive moves in banking and credit card stocks

The prospect of the incoming Trump Presidency and Republican term in Congress increases the prospects of a rollback in regulations and consumer protections put in place after the global financial crisis of 2008 and enforced aggressively under the current administration.

For instance, last year, the Biden Administration proposed cracking down on excessive "junk" fees, like bounced check and overdraft fees, and directed the Consumer Financial Protection Bureau (CFPB) to make it easier for consumers to "break up with their bank," among other measures meant to shield consumers from certain banking charges. However, the change in administration is likely to either reverse or prevent those regulations from going into effect.

Credit card companies are some of the bigger fee-chargers in the banking industry. While American Express should benefit from the regulatory rollback, Synchrony Bank, which typically issues private-label credit cards for other brands and, thus, caters to more of a lower- and middle-class clientele than American Express, rallied even more. Synchrony's super-low valuation at just 8 times earnings to start the day was also a factor and, probably, at least in part due to this regulatory overhang. Hence, the stock popped very significantly.

Finally, on regulation, Republicans may seek to reduce capital cushion mandates. That would allow banks to use more of their capital for lending and shareholder returns, potentially boosting earnings growth.

In addition to banking deregulation, there will likely be relief on the merger and acquisition front. The Biden Administration has been known to be very aggressive in attempting to block mergers. Therefore, there could be more tie-ups in the American regional banking system, as the U.S. banking system is still more fragmented than those in many other countries. Huntington Bancshares is a $25 billion market-cap regional bank and could be either an acquirer or acquiree.