Legacy retail brokerages—specifically Charles Schwab (NYSE:SCHW)—make a massive amount of money from customers leaving their money sitting idle.

In other words, inertia is extraordinarily profitable.

A Citrini Research report published on Sept. 22. estimates Charles Schwab earns nearly $9 billion in additional annual pre-tax profit from pricing customer cash and margin loans less competitively than Interactive Brokers Group Inc. (NASDAQ:IBKR).

Citrini said the high rates legacy brokers charge, and the low rates they pay, “only exist because of consumer ignorance and the friction of switching platforms.”

So What Happens When AI Agents Remove Both?

The gap starts with cash. Citrini’s second-quarter 2026 comparison shows Schwab paying about 0.19% on $246 billion of bank deposits. Interactive Brokers’ modeled comparable rate is 2.23%.

That difference alone produces an estimated $5 billion annual benefit for Schwab.

Another roughly $2.2 billion comes from brokerage cash. The final $1.8 billion comes from margin lending, where Schwab charges 5.68% versus 4.10% at Interactive Brokers.

Add everything together and Citrini arrives at approximately $8.99 billion in annualized pre-tax profit.

Why Does the Gap Survive?

“Inertia rent works because people are lazy,” Citrini Research said.

Consumers tolerate unused subscriptions, overpriced insurance and poorly yielding cash because switching requires attention and effort. AI agents do not have that problem.

Citrini called the rates gap one of the longest-standing and most irrational freebies in retail finance.

It named E-Trade, Fidelity and Vanguard alongside Schwab as the big legacy platforms that benefit.

Bucket Schwab average balance Schwab rate IBKR rate Gap Annual benefit to Schwab
Bank deposits $246.35 billion 0.19% paid 2.23% paid 2.04 points $5.03 billion
Brokerage client cash $108.84 billion 0.22% paid 2.23% paid 2.01 points $2.19 billion
Margin lending $112.14 billion 5.68% charged 4.10% charged 1.58 points $1.77 billion
Total $8.98 billion
Source: Citrini Research, company filings; second quarter 2026, annualized

Posted margin rates show the same pattern. On a $25,000 loan, Interactive Brokers lists 5.38%, while Schwab lists 11.58%, more than twice as much, according to a comparison published by Interactive Brokers.

In Citrini’s view, Interactive Brokers is no harder to use than its larger rivals, yet it lets clients trade on market terms. The report also noted that Robinhood Markets Inc. (NASDAQ:HOOD) offers competitive rates.

Why AI Agents Threaten The Lazy Cash Model

The trigger is Meta Platforms Inc.’s (NASDAQ:META) consumer agent, Muse. According to Citrini, Muse reached the No. 1 spot in the App Store, with more than 700,000 downloads on its first day.

Meta AI chief Alexandr Wang said on X that “the muse reception has honestly been beyond our biggest dreams.”

Citrini groups Schwab’s spread under what it calls “inertia rent.” The idea is simple. People let money sit because moving it means jumping through hoops.

An agent does not behave that way. Citrini said an agent’s natural state is to stay alert, constantly reviewing a user’s spending for waste. Moreover, machines have no habits and do not respond to advertising.

The report also describes the change in plain terms. Every day, it said, new cases will appear where friction that once made money becomes a cost for companies that do not adapt.

Citrini Research said agents could “begin to cut in on margins for companies that have built up their moat around rent-seeking” from inertia and other forms of friction.

For investors, that could become one of AI’s most important second-order effects.

The first AI trade rewarded companies selling computing power.

The next one may punish companies whose profits depend on customers not bothering to shop around.

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