Independent power producers own generating plants and sell the electricity into wholesale markets at prices nobody guarantees them — unlike a regulated utility, which earns an approved return. That is why they became the listed proxy for artificial-intelligence electricity demand, and why they fall together when Texas changes the rules. On 3 August the state paused new large-load interconnections pending an audit by the Public Utility Commission and the grid operator ERCOT, facing 474 gigawatts of requests — roughly five times the state's record peak demand, about 90% of it data centres. The order requires developers to disclose tax incentives, self-generation plans and water use before proceeding.

One label, five unrelated situations

Treating these five as a single falling trade is the error. Over the past 30 days to 7 August they ran from Constellation +10.4% to NRG -14.1% — a 24.5-point spread, and an equal-weighted average near -3.6% that describes none of them. Over twelve months the four genuine merchants average about -20%, but the range is wide: Vistra -31.6%, NRG -22.9%, Constellation -19.8%, Talen -7.4%. Drawdowns from 52-week closing peaks are deeper still — Vistra -35.5%, NRG -35.8%, Constellation -33.2%.

AES, the fifth, is not a merchant generator and not an equity story at all: a consortium led by Global Infrastructure Partners and EQT agreed to buy it for $15.00 a share in cash, approved by shareholders in June. It closed at $14.73 — a 1.8% spread to the deal price. Its steadiness is arbitrage, not power fundamentals, and it flatters any average it sits in.

The fuel leg of the bear case is also inverted. Gas costs are not squeezing these plants: Henry Hub futures fell nearly 15% through July to $2.75 per million British thermal units. The pressure is on the power side in Texas, where supply timing, not fuel, set prices. In the mid-Atlantic the opposite holds: PJM's capacity auction for 2028/29 cleared at the $325 per megawatt-day cap and still came up 6,831 MW short of its reliability requirement.

Where the businesses actually stand

Constellation Energy, the Baltimore owner of 32,400 MW led by the largest unregulated US nuclear fleet, raised 2026 adjusted operating earnings guidance to $11.50-12.50 from $11-12 on second-quarter earnings of $2.55 a share, up $0.64. It added roughly 920 MW of nuclear supply contracts at an 18.5-year average tenor — including 176 MW to Walmart, a retailer's first — putting about 30% of its clean baseload under contract, and sold a 606 MW Texas gas plant for $860m, about $1,420 per kilowatt. It is leading the group. Business verdict: CONTRADICTS the de-rating.

Vistra, the Irving, Texas generator with 38,700 MW and 4.3m retail customers, lifted adjusted EBITDA 31% to $1.767bn, with generation up 68%, and reaffirmed 2026 guidance of $6.8-7.6bn and its 2027 range of $7.4-7.8bn — excluding the pending Cogentrix acquisition and a Meta nuclear supply deal worth roughly $700m more. Reported revenue fell 5.5%, but operating margin widened to 13.8% from 12.1%: hedged generation. Verdict: CONTRADICTS.

NRG Energy, the Houston retail-and-generation group serving six million customers, is the exception. Adjusted EBITDA rose 34% to $1.2bn almost entirely on the LS Power acquisition, while adjusted earnings per share fell to $1.49 from $1.73, sending the shares to a 52-week low. Gross margin narrowed to 14.5% from 16.5%. It has aligned on terms for a 1.2 GW gas plant for an unnamed hyperscaler — $3.2bn of capex, $500m of annual EBITDA — but it is pre-final-investment-decision, and growth spending pushes its leverage target from 2028 to 2029. Verdict: CONFIRMS.

Talen Energy, a 10.7 GW Houston producer built around the Susquehanna nuclear station, lost $92m in the quarter and has not reported since the Texas freeze. Verdict: INCONCLUSIVE.

Valuation

Vistra is the dislocation: 6.96x trailing enterprise value to EBITDA, the cheapest here against Constellation's 14.2x, NRG's 11.4x and Talen's 31.6x, and 15.5x forward earnings against 59.8x trailing, on consensus 2026 earnings of $9.06 (+90%). Constellation has compressed from 41.3x trailing earnings in May to 26.2x now against 23.0x forward — below the ~35x forward premium logged as a risk earlier this year. NRG at 13.3x forward is cheap but with deteriorating earnings attached — closer to a justified de-rating. Talen, on negative trailing earnings and the richest EBITDA multiple, is the least de-rated, not the safest.

The tape agrees only with NRG. Vistra and NRG both saw their 50-day averages cross below their 200-day on 4 August — the same session, the day after the freeze, when NRG fell 15.5% and Vistra 8.2%. Constellation's chart still reads bearish while the price has risen 10.4% in a month; Talen only turned negative on 6 August.

The setup

Where it stands — One policy shock, four different businesses: two raising or holding guidance, one missing, one silent. Would confirm — NRG's Texas segment stabilising with Houston power back above its $52/MWh planning assumption. Would invalidate — Vistra cutting its $7.4-7.8bn 2027 range at the third-quarter update after Cogentrix closes. Watch next — Talen's next results, its first commentary since the 3 August Texas freeze. Valuation — Vistra 6.96x trailing EV/EBITDA and 15.5x forward earnings; Constellation 26.2x trailing, 23.0x forward, versus 41.3x in May.