Jamie Dimon fans have been rewarded with some of the best returns among Wall Street giants over the years, but his firm’s recent missteps mean he’s lost at least one devotee.

Mike Mayo, a senior analyst at Wells Fargo & Co., wrote in a note Monday that JPMorgan Chase & Co.’s “reduced transparency, financial discipline, and shareholder consideration” call into question the premium that the biggest U.S. bank enjoys based on past performance. Dimon, the bank’s 65-year-old chief executive officer, has led the company since 2005, and the stock has almost quadrupled under his watch, outpacing all major competitors.

“JPMorgan’s premium is owed partly to the CEO, who has one of the best stock-price performance of bank CEOs of this generation,” Mayo wrote. “The difference now, however, is that JPMorgan seems to be pushing for growth by hurting the features that contributed to its past success.”

Mayo cut his rating on the stock to equal weight from overweight last month after the company reported fourth-quarter results, citing “front-loaded spending for less certain back-ended benefits.”

Shares of New York-based JPMorgan are down 2.8% this year, one of the worst performers in the 24-company KBW Bank Index, which is up 7% in the period.

JPMorgan executives told investors last month that they expect expenses to rise 8.6% this year to $77 billion excluding legal costs. More than half of the expected increase is tied to investments. The company plans to spend about $15 billion in 2022 on initiatives including cloud capabilities, branch expansion and card marketing.

The bank has also been on a buying streak, making acquisitions and strategic investments at the fastest pace since at least the financial crisis. In his annual shareholder letter last year, Dimon declared the arrival of fintech and big tech to the banking landscape, and he’s vowed to spend whatever it takes to stay ahead.

In his note, titled “‘Love is Blind’ for the CEO,” Mayo cited:

• Transparency. Investors deserve targeted metrics for its transformation even if it won’t hold an investor day, Mayo said.
• Expenses. JPMorgan is increasingly willing to sacrifice returns to gain share. Questions around spending include whether the firm’s managers, many of whom are in new positions, “feel secure in challenging the CEO.”
• Technology. It’s unclear how much of JPMorgan’s technology spending is “needed to fix legacy issues,” but Mayo questioned why these actions weren’t taken sooner given the firm’s 2014 annual report, which warned that Silicon Valley was coming to banking.
• Shareholders. On the most recent earnings call, Dimon “stressed that it’s too bad if shareholders don’t like JPMorgan’s spending (at least as related to employee pay). • This is the same CEO who would buy more of his own company’s stock when it dislocated too much as a sign that he was aligned with shareholders.”
• Acquisitions. The track record of banks successfully buying other firms is “limited,” Mayo said.

This article was provided by Bloomberg News.