Stock prices in half-cents are coming soon to a brokerage near you.

The Securities and Exchange Commission on Wednesday approved a change to market rules that would cause the prices of many stocks to be quoted in increments of $0.005.

The rule change—which could potentially affect thousands of stocks and exchange-traded funds—is part of an overhaul of market plumbing that SEC Chair Gary Gensler initiated after the GameStop () trading frenzy of early 2021. It was approved in a unanimous vote by the agency’s five commissioners, including two Republicans who have in the past opposed elements of Gensler’s agenda.

SEC officials say the rule change will help lower costs for investors by narrowing bid-ask spreads—the difference between the buying and selling prices of stocks. Bid-ask spreads eat into investors’ gains when they trade in and out of stocks. If the spreads are tighter, investors save money.

For many stocks, such as Ford Motor () and Snap (), the bid-ask spread is often 1 cent—and it can’t get smaller because of longstanding SEC rules that set the minimum price increments for most exchange-listed stocks at a penny.

Now, the SEC is creating a two-tier system with two minimum price increments, or “tick sizes.” Some stocks would continue to have 1 cent ticks, but others—those where the bid-ask spread is frequently stuck at around 1 cent—would have their minimum price increments reduced to half a cent.

“The one-penny minimum has become outdated and too wide for many stocks in today’s markets,” Gensler said Wednesday.

Gensler, a hard-charging regulator known for butting heads with Wall Street, took the helm of the SEC soon after the January 2021 meme-stock craze spurred scrutiny of how brokers and middlemen handle small investors’ stock trades. He kicked off a review that led to several ambitious proposals to rewrite market rules. Some of his most contentious proposals still remain to be finalized in the face of intense opposition from industry groups and Republicans on Capitol Hill.

With tick sizes, Gensler appears to have dropped the most disputed elements of an original proposed version from December 2022 to win consensus. Both the Managed Funds Association, a hedge-funds trade group, and left-leaning advocacy group Better Markets praised the SEC’s rule change on Wednesday, agreeing that reducing tick sizes to half a penny would lower costs for investors.

“Today’s decision was a long-awaited result, which will benefit investors of all sizes,” said Brad Katsuyama, chief executive of IEX Group, the stock-exchange operator made famous by Michael Lewis’s book “Flash Boys.”

An estimated 1,788 stocks would qualify for the tighter, half-penny ticks based on how they traded last year, according to an analysis released Wednesday by the SEC. The agency hasn’t provided a list of which stocks would be affected. The rule change is set to take effect in November 2025.

The initial proposed version of the SEC’s rule change from 2022 envisioned a four-tier system, in which stocks could have tick sizes of one-tenth of a penny, two-tenths of a penny, half a penny and 1 cent. Brokerages and trading firms complained that the proposal was too complex and would lead to stocks constantly flickering between price levels just $0.001 apart.

One element of Wednesday’s rule change could upset big U.S. stock exchanges. Besides reducing tick sizes, the SEC slashed a longstanding cap on how much exchanges can charge for executing trades, cutting it to 10 cents per 100 shares from 30 cents.

SEC officials have argued that if they reduced tick sizes, they also needed to reduce the so-called access fee cap in parallel to prevent potentially abusive trading behavior. Many brokers and trading firms also lobbied for a lower cap, saying it was too high.

“Our initial assessment suggests that the commission’s rules lack foresight and do not consider the intricate dynamics of the equity market,” Nasdaq said in response to Wednesday’s vote. The New York Stock Exchange declined to comment.

It has been years since the last major shift in tick sizes. For most of the 19th and 20th centuries, U.S. stocks were priced in increments of one-eighth of a dollar. In 1997, the NYSE shifted to sixteenths of a dollar—which traders called “teenies”—following a similar move by Nasdaq.

The SEC pushed the exchanges to adopt pricing in dollars and cents in 2001, a landmark event called decimalization. Decimalization was ruinous for old-school specialists on the NYSE floor and market-making firms in Nasdaq stocks, which had previously made ample profits due to the wide spreads, and a new breed of tech-savvy high-speed traders emerged to take their place.