10 Stocks Collapse Overnight

Ten stocks joined Wall Street’s lackluster performance on Monday, as investor sentiment was dampened by a series of negative developments, including a lackluster outlook and earnings, as well as share sale programs.

Meanwhile, Wall Street’s three major indices all finished in the red. The Dow Jones fell by 0.45 percent, the tech-heavy Nasdaq dropped by 0.30 percent, and the S&P 500 declined by 0.25 percent.

In this article, we name the 10 companies with the worst performance on Monday, alongside the reasons behind their decline.

To compile the list, we focused exclusively on stocks with $2 billion in market capitalization and at least 5 million shares in trading volume.

A man in black suit holding a tablet looks at stock market data on a monitor. Photo by Tima Miroshnichenko on Pexels

10. Under Armour Inc. (NYSE:UAA)

Under Armour extended its losing streak to a third consecutive day on Monday, shedding another 5.88 percent to close at $5.12 apiece following the rating and price target downgrades from two investment firms.

In its market note, Truist Securities lowered its price target for shares of Under Armour Inc. (NYSE:UAA) to $5 from $7 previously, while maintaining a “hold” rating, amid tariff headwinds that continue to put incremental pressure on its bottomline.

While Under Armour Inc. (NYSE:UAA) has previously expressed optimism about emerging positive indicators, Truist said it was waiting for more signs that turnaround initiatives and heavy brand investments would help drive demand before meriting an upgrade.

For its part, Stifel gave a price target higher than Truist, at $9, albeit a downgrade from the $10 previously. Stifel also maintained a “buy” recommendation for the stock.

According to Stifel, its revision reflected Under Armour Inc.’s (NYSE:UAA) weaker outlook guidance for the second quarter of fiscal year 2026, adding that the full fiscal 2026 could be half of 2025 levels.

On Friday, Under Armour Inc. (NYSE:UAA) said it narrowed its net loss for the first quarter of fiscal year 2026 by 99 percent to $2.6 million from $305 million in the same period last year.

9. Transocean Ltd. (NYSE:RIG)

Transocean dropped its share prices by 6.13 percent on Monday to close at $2.91 apiece as investors soured on the company’s planned debt-to-equity swap program that could result in a potential dilution of existing shares.

In a regulatory filing on Monday, Transocean Ltd. (NYSE:RIG) said that its wholly owned subsidiary, Transocean International Ltd., entered into separate, individual agreements with certain shareholders for its 4-percent senior guaranteed exchangeable bonds due this year.

Under the agreement, the bondholders agreed to swap $39.7 million of bonds for shares of Transocean Ltd. (NYSE:RIG) at a price yet to be determined. The price would be based on the daily volume-weighted average price over a five-day trading period, including August 11.

In recent news, Transocean Ltd. (NYSE:RIG) widened its net loss in the second quarter of the year by 663 percent to $938 million from only $123 million in the same period last year.

Revenues, on the other hand, increased by 14.7 percent to $988 million from $861 million previously.

As of July 2025, the company has a total backlog of $7.2 billion.