NEW YORK, January 4, 2026, 07:30 ET — Market closed
- Eos Energy Enterprises last closed up 13.18% on Friday at $12.97, with the last reported after-hours print at $13.04. 1
- Options trading in EOSE spiked on Friday, led by activity in long-dated call options, Nasdaq data showed. 2
- Short interest remains elevated, a setup that can amplify moves when the stock rises and bearish bets are forced to unwind. 3
Eos Energy Enterprises, Inc. shares ended Friday’s session up 13.18% at $12.97, after the first U.S. trading day of 2026 put smaller, higher-volatility names back in focus. The stock was last indicated at $13.04 in after-hours trading. 1
The jump matters because Eos is one of the market’s more heavily shorted energy-storage names, which can turn a routine bounce into a faster rally as bearish traders buy shares back to limit losses. Friday’s move also came as small caps outperformed in a broader risk-on tilt to start the year. 4
Options activity underscored the renewed appetite for risk. Nasdaq data compiled by BNK Invest showed 92,958 Eos options contracts had traded by mid-afternoon Friday, equivalent to about 9.3 million shares, with notable volume in a $37 strike call expiring in January 2028. (A call option gives the buyer the right to buy shares at a set price by a set date.) 2
Short interest — the number of shares borrowed and sold by traders betting on a decline — stood at 82.79 million shares as of Dec. 15, or 29.70% of Eos’ public float, MarketBeat data showed. The “days to cover” ratio was 4.8, meaning it would take about 4.8 days of typical volume for short sellers to buy back shares and close positions. 3
Eos was not alone in rallying across the energy-storage complex on Friday. Fluence Energy rose about 16%, while Stem gained about 13% and Energy Vault advanced roughly 6%, based on the latest available pricing data.
The broader tape helped. The Russell 2000 climbed 1.1% on Friday as U.S. stocks opened the year with a “buy the dip” tone, with the Dow up 0.66% and the S&P 500 adding 0.19%, according to Reuters. 4
“Joe Mazzola, head of trading & derivatives strategist at Charles Schwab, told Reuters the market is seeing a ‘buy the dip, sell the rip’ mentality,” as investors traded around short-term swings. 4
Eos, based in Edison, New Jersey, makes zinc-bromine battery energy storage systems used for utility and industrial projects. The company has also secured federal support in recent years, including a U.S. Department of Energy loan guarantee tied to expanding manufacturing lines in Pennsylvania. 5
In the past year, the company has pointed investors to demand tied to grid reliability and data-center growth. Eos and Talen Energy announced a partnership in October to develop energy storage capacity across Pennsylvania, Reuters reported at the time. 6
Before Monday’s open, traders will be watching whether Friday’s surge holds or fades as liquidity returns after the holiday period. Next week’s U.S. labor-market data is also on the calendar as investors handicap the path of interest rates, a key input for smaller growth companies. 4
The next company-specific catalyst is earnings. MarketBeat lists Eos’ next quarterly report as estimated for March 3 after the close, though the company has not confirmed the date. Investors will be looking for updates on delivery pace, manufacturing ramp and cash needs after a volatile 2025. 1
