Why is Fastly stock plunging today?

Fastly plunged as much as 34.45% after Q1 2026 results, with revenue of $173.0M up 20% year over year but still not enough to justify the stock’s roughly 270% three-month rally. Q2 guidance for $170.0M-$176.0M revenue and $0.05-$0.08 non-GAAP EPS implies a sharp sequential earnings step-down from Q1’s $0.13, while infrastructure capex is set to rise to 10%-12% of revenue from 5% in 2025. Piper Sandler cut its target to $27 from $30 and maintained Neutral, citing growth concerns and a beat that was only in line with expectations.

Analysis

The setup looks less like a fundamental re-rating and more like an unwind of crowded momentum with leverage to a very narrow narrative. When a name gaps from “AI winner” to “capex reacceleration + sequential earnings reset,” the first-order pain is in the stock, but the second-order effect is on the entire cohort of high-multiple edge/security beneficiaries: investors become less willing to pay for revenue quality unless they see durable operating leverage. That matters because Fastly’s guide implies growth is being defended with heavier infrastructure spend, which reduces the scarcity premium the market was assigning to this story.

The key issue is not the absolute guide, but the implied slope of future margin expansion. If capex doubles as a percentage of revenue, the market will start discounting whether incremental growth is actually self-funding or simply being bought, which is usually when multiples compress fastest. In that regime, even modest misses or any signs of customer concentration can trigger another 10-20% de-rating over the next 1-2 quarters, because the valuation support was built on the assumption that AI-driven demand would scale without balance-sheet drag.

There is also a positioning air pocket risk: large call buying into the print suggests a dealer-unwind dynamic that can extend downside beyond what the earnings revision alone would justify. That can make the first 24-72 hours look oversold, but it also means reflexive bounces are likely to be sold until the market sees a clean evidence point—either sustained upside in security revenue, an inflection in operating margin, or commentary showing capex moderates after capacity catch-up.

The contrarian case is that the market may be extrapolating too aggressively from one quarter into a full-year deterioration. If security adoption is truly accelerating, Fastly could still grow into the spend, and the current drawdown may reset expectations enough to set up a tradable squeeze if management delivers one more quarter of clean execution. But that is a “show me” story now, not a valuation argument.

Key Decisions for Investors

• Short FSLY into post-earnings volatility over the next 1-3 weeks; use a tight stop above the pre-earnings VWAP/recent breakout zone. Risk/reward favors another 10-15% downside if the market continues to de-rate the multiple on capex and sequential EPS compression.
• If forced to own the theme, switch from FSLY to a basket trade: long higher-quality cybersecurity/platform names with durable FCF and short FSLY as the beta-funded leg. This isolates the selloff to execution risk while keeping exposure to the broader AI/security spend cycle.
• Buy short-dated puts or put spreads on FSLY for the next earnings-to-guidance reset window. Best structure is 30-60 DTE put spreads to monetize another leg lower without paying full implied vol if the squeeze has already peaked.
• Fade any sharp intraday rebound in FSLY unless volume confirms re-accumulation. The likely path is a dead-cat bounce followed by another leg lower as analyst model cuts and valuation discipline spread through the small-cap software space.
• For contrarian capital, wait for a second-quarter execution beat or a clear capex moderation signal before initiating a long. Absent that, the downside is driven by multiple compression, while upside requires a higher bar: proof that growth can reaccelerate without eroding margin structure.