374Water registers $50M ATM equity offering; stock jumps

What happened

374Water Inc. (Nasdaq: SCWO), a waste-treatment technology company, filed a prospectus on August 11, 2026, for an at-the-market (ATM) equity offering of up to $50 million of its common stock. The company entered into a sales agreement with Robert's & Ryan Inc., dated August 10, 2026, to sell shares from time to time at prevailing market prices. This agreement replaces a prior ATM sales agreement with Lake Street dated December 23, 2025, under which no further sales will be made.

The filing triggered heavy trading and a price increase. On August 11, volume was 259,300 shares, more than four times the average of about 59,300, and the stock closed at $2.52, up 8.6% from the prior close of $2.32. The filing itself notes the last reported sale price on June 11, 2026 was $2.45 per share.

374Water describes itself as a global industrial technology company that uses its proprietary AirSCWO system to destroy and mineralize organic wastes, including sewage sludge, biosolids, food waste, and PFAS 'forever chemicals,' converting them into water, minerals, and heat energy. The company was formed in 2005 as PowerVerde and merged with 374Water in April 2021.

The filing

The filing is a Form 424B5, a prospectus supplement used to detail a specific offering under an existing shelf registration. 374Water's shelf registration allows for up to $100 million of various securities, and this ATM offering is for common stock up to $50 million.

The company is a 'smaller reporting company' and its public float is about $27 million, calculated from 11,018,601 shares held by non-affiliates at $2.45 per share. As a result, it is subject to 'baby shelf' rules under General Instruction I.B.6 of Form S-3, which limit sales to one-third of the public float in any 12-month period. After deducting shares sold in the prior 12 months, approximately $1.142 million worth of shares remain available under the shelf.

Sales under the ATM can be made directly on The Nasdaq Capital Market or other trading markets. Robert's & Ryan is not required to sell any specific amount but will use commercially reasonable efforts, and will receive compensation of up to 3.0% of gross proceeds. The company intends to use net proceeds for general corporate purposes and working capital.

What this means

An ATM offering is a mechanism that lets a company sell new shares gradually into the market over time, rather than in a single underwritten deal. This allows the company to raise capital opportunistically, but it also dilutes existing shareholders when shares are sold. The filing notes that, assuming an offering price of $2.45 per share, up to 20.4 million new shares could be issued, increasing the share count from about 17.7 million to as many as 38.1 million, although actual sales depend on market conditions.

The 'baby shelf' rule is designed to limit how much a company with a small public float can sell using a shelf registration, capping sales at one-third of the public float per year unless the float exceeds $75 million. This is part of why the company states that only about $1.1 million in shares are currently available to sell, despite the $50 million headline amount. The company may need to replenish the shelf or see its float grow before raising the full amount.

Investors reacted to the news with a price increase, which is notable given the potential dilution, but the filing does not explain the market's reaction. The rise could reflect speculation that the company will use the proceeds to fund its waste-treatment technology deployment, but the filing does not provide such a reason.

Next, the company will decide when and how many shares to sell under the ATM, likely based on its capital needs and market conditions. Sales are not mandatory, and the company could choose to sell only a small portion or none.