FAC vs SLDP: Which Is the Better Buy in 2026?

Same yardstick, side by side (as of August 2026). Valuation lined up like this is most meaningful for two names in the same corner of the market, which these are. Figures are approximate; verify before investing.

The metrics above tell you which is the marginally better business. The bigger risk for most people is not picking the slightly worse stock, it is over-concentrating. FAC and SLDP share themes, so owning both, or adding either to what you already hold, can quietly push a large share of your portfolio into one bet.

This is the part a generic comparison page cannot answer, because it depends on what you own. Connect your brokerage and Walnut shows your real, combined FAC and SLDP exposure, flags overlap with your existing positions, and tells you if adding one would tip you past a concentration you are comfortable with, read-only by default, with your login staying at your broker. Walnut is not an investment adviser.

Factorial Energy develops solid-state battery technology for electric vehicles and other high-performance applications. Its proprietary platforms, FEST (Factorial Electrolyte System Technology) and Solstice, are designed to deliver higher energy density, faster charging, and improved safety versus conventional lithium-ion cells. The company works through joint development agreements with major automakers including Mercedes-Benz, Stellantis, Hyundai, and Kia, and has publicly validated automotive-sized cells at roughly 375 Wh/kg with fast-charge and cold-weather performance milestones. It became publicly traded on Nasdaq under the ticker FAC (with warrants FACWW) after combining with Cartesian Growth Corporation III in June 2026 at an enterprise value of about $1.3 billion.

Full FAC guide

Solid Power is a Colorado-based battery-technology company developing all-solid-state batteries built around a sulfide-based solid electrolyte, which it positions as a potentially safer, higher-energy-density alternative to today's lithium-ion cells. A central part of its pitch is that the electrolyte can be processed using existing lithium-ion manufacturing equipment, a "drop-in" compatibility the company argues lowers the barrier to commercialization. The business has shifted toward a capital-light model focused on supplying solid electrolyte and licensing its technology to partners rather than building full cell-manufacturing gigafactories itself, with much of the contemplated commercial-scale cell production happening through partners, particularly in Korea.

Full SLDP guide

Both fit overlapping themes, but they are not interchangeable. The useful comparison is which set of drivers and risks you want exposure to.

• FAC drivers: Automaker partnerships and validation milestones; Solid-state technology differentiation.
• SLDP drivers: Automaker and battery-partner relationships; Electrolyte-supplier and licensing model.

A faster-growing, richer-valued name usually swings harder, so it suits a longer horizon and a higher tolerance for volatility; a steadier, more cash-generative business suits a more conservative or income-minded investor. The honest test is which set of risks you could hold through a drawdown: Factorial is pre-revenue and deeply unprofitable, with a large accumulated deficit and ongoing cash burn, so it depends on hitting commercialization milestones and likely raising more capital before running out of runway around early 2028. For SLDP, commercialization is unproven: Solid Power generates minimal revenue (largely partner milestones and grants) and is years away from any solid-state battery reaching mass production, so the timeline is long and uncertain.

Growth-minded investors who believe the theme has years to run tend to accept the richer multiple for more upside; value-minded investors lean toward the cheaper forward earnings and steadier profile. Pick FAC if you believe its drivers more; SLDP if you believe its. Many investors hold both, but since they share themes, that is a concentrated bet, not diversification. Decide deliberately and check overlap. For the full detail, see the FAC and SLDP guides.

FAC. Standard valuation multiples do not apply because Factorial has essentially no revenue and negative earnings, so the market is pricing an option on future commercialization rather than current cash flows. The de-SPAC valued the company near $1.3 billion, but heavy trust redemptions and post-listing volatility pushed the share price to around $8 and market cap toward roughly $0.9 billion by July 2026, versus a 52-week range of about $7.89 to $25.33.

SLDP. For a pre-commercial company like Solid Power, traditional earnings multiples are not meaningful because there is little revenue and no profit. What matters more is the size of the cash cushion relative to annual burn (the runway), progress on technical and partner milestones, and whether the electrolyte-supplier and licensing model produces real orders. The valuation is speculative and can move sharply on partnership news, financing events, or shifts in EV and solid-state-battery sentiment. Figures are approximate and tied to the asOf date.

Headline figures (approximate, JULY 2026): FAC shows revenue (ttm) ~$0 (pre-revenue), net loss (fy2025) ~$73.8M, accumulated deficit ~$255.6M, share price ~$8; SLDP shows revenue and grant income (q1 2026) ~$3.1 million, down sharply year over year and driven mainly by SK On and U.S. Department of Energy milestones; effectively pre-revenue from a product-sales standpoint, trailing-twelve-month revenue ~$15.3 million (largely development and grant income, not commercial product sales), net loss (q1 2026) ~$13.0 million, or about ~$0.06 per share, narrower than the ~$15.2 million loss a year earlier, cash and investments ~$435 million total liquidity (cash, equivalents, and available-for-sale securities) as of March 31, 2026, with no debt.

FAC and SLDP are related but distinct: same themes, different businesses and risks. Neither wins in the abstract; the right pick is whichever thesis you actually believe, sized so you are not over-concentrated in one theme. Walnut can show your combined FAC and SLDP exposure against your real portfolio. It is not an investment adviser.