An e-mail chain making the rounds on Wall Street appears to show a senior banker at PJT Partners reprimanding subordinates for not promptly responding to an email that came in at 3 a.m.

“We’re working on these now (and have been), but we didn’t receive them until 3 am our time and were already in bed,” according to a 6:38 a.m. e-mail that kicked off the viral chain on May 13.

The email prompted an unsympathetic reply from the person in charge, according to the screenshot, which was first posted on Instagram by @arbitrageandy with the names redacted.

“To be clear I am working ET time and I expect my junior team to notify me when they log off,” the boss responded. “Not an excuse 3 am,” this person said. “I sleep [an] average of 5 hours or less. Expect the same or more from my junior team especially on live deals. Please turn around my comments and work as fast as you can.”

The chain is titled “Bid Deck,” an investment banking term for an in-depth financial presentation to clients. Such presentations are notoriously time-consuming, especially for the lowest rung of investment bankers, a group that includes so-called associates and analysts.

Wall Street analysts tend to make under $100,000 a year, while associates tend to earn between $120,000 to $150,000, according to Glassdoor.com.

Wall Street has come under the microscope before for its grueling treatment of lower-level staff, including in 2013 when 21-year-old, London-based Bank of America intern Moritz Erhardt was found dead in his apartment after working for three nights straight. A post-mortem investigation found Erhardt died from an epileptic seizure, and his family said they believed it was caused by a lack of sleep.

While some large investment banks have since vowed to make life easier on lower level bankers — especially as they seek to compete with the tech sector for talent — smaller “boutique” investment banks have continued to lean heavily on its junior analysts and associates to execute complicated financial deals.

PJT — a boutique bank that specializes in the competitive realm of special situations advisory work — declined to comment on the e-mail chain while defending its work culture.

“While we do not comment on personnel matters, maintaining a culture of respect, collaboration and a commitment to excellence is our highest priority at PJT Partners,” said a spokesperson. “We remain committed to supporting each other and serving our clients during this time.”