VST Q1 2026: The AI-Power Cohort Going Into Earnings

VST Is A Different Stock Post-2023

Pre-2023, VST traded as a vanilla independent power producer with sub-3% earnings-day moves. Post-2023, the AI-data-center thesis transformed the reaction profile — the 8-print cohort since Q1 2023 has a median earnings-day |move| of 7.8%, including a +14.2% (Q2 2024) and a -11.6% (Q1 2024). The cohort retrieval down-weights pre-2023 VST analogs and emphasizes 2023+ prints, plus cross-ticker analogs from CEG and TLN with similar contracted-data-center exposure.

Across the combined 17-print 'AI power' cohort, the 5-day forward median is +1.2%, the 10-day median is +2.6%, and the IQR is [-5.4%, +9.8%]. Notably, the 10-day continuation is more reliable than the 5-day — when the print confirms data-center momentum, the move tends to extend into the following week.

Contracted-MW Is The Key Disclosure

The feature attribution from the cohort surfaces one dominant condition: incremental contracted megawatts disclosed on the call (or in the slide deck), along with any commentary on the customer mix (hyperscaler vs. enterprise). The cohort splits:

• New hyperscaler contract announced + raised long-term capacity guide (n=5): 5-day median +8.7%, hit-rate 100%
• Existing-contract MW expansion only (n=6): 5-day median +1.8%, hit-rate 67%
• No new contracted-MW disclosure + flat capacity guide (n=4): 5-day median -4.6%, hit-rate 25%
• Capacity-factor and PPA pricing trends: secondary feature, amplifies the contracted-MW signal by ~2pp

Pre-Print Setup

Heading into the May 7 open, VST has drifted +6.2% over the prior 10 sessions on heavy call-buying (call/put ratio at the 90th percentile of the trailing year). Options-implied move sits at ~8.4%, in line with the historical 8-print AI-power cohort median.

The conformal 80% band off the cohort sits at [-7.9%, +12.3%] for the 5-day forward. The pre-drift-positive subset of the cohort actually has a slightly tighter band ([-5.2%, +11.8%]) and a higher 5-day median (+2.4%), because positive drift into VST prints has correlated with subsequent contracted-MW announcements.

What To Watch On The Call

The post-call cohort match weights three signals: any new hyperscaler customer announcement, expansion of capacity guidance for 2027-2030, and PJM/ERCOT capacity auction commentary. These three together drive ~75% of the within-cohort 10-day return variance.

Agent systems pricing VST off earnings should defer the cohort retrieval until ~45 minutes after the call begins — Vistra typically discloses contracted-MW updates in the prepared remarks, and the chart shape stabilizes only after the market processes that disclosure.