FISN ▼ -10.8% - Deep Fission, Inc. We are short Deep Fission ($FISN), a Nasdaq-listed small modular reactor (SMR) startup planning to bury a 5–15 MWe reactor one mile deep in a 40–60-inch borehole. Its SMR is not cost-competitive, already facing delays, and will likely never be commercialized.  -- ICEBERG RESEARCH 24-SEP-2026 10:26 AM ET