A 15 percent headline is an intraday print, not the close. Constellation Energy finished Tuesday 6 October 2026 at $300.40, up $32.78, or 12.25 percent, from Monday’s $267.62 close on Nasdaq. The high was $309.80, 15.8 percent above Monday, and the stock gave back $9.40 into the 4 p.m. Eastern close. CNBC, updating a story at 2:38 p.m. that day, said the shares had soared 15 percent. That sentence matches the high, not the print that cleared.
The megawatt headline is two contracts, not a reactor wired to a private Google campus. Constellation’s 6 October release pairs a 20-year agreement for 890 megawatts of new nuclear output with a 15-year agreement for 2,700 megawatts that the company says stays in the PJM market. Talen Energy, which did not sign, closed at $373.11, up 12.43 percent, slightly ahead of Constellation. Alphabet’s Class A shares closed at $347.68, up 0.35 percent. The buyer did not re-rate. The closes used here are Tuesday’s official prints.
Key facts
- Constellation (Nasdaq: CEG) closed Tuesday 6 October 2026 at $300.40, up 12.25 percent from Monday’s $267.62, according to Nasdaq. Volume was 13,482,660 shares, roughly 4.4 times the prior 20 sessions. The high was $309.80 and the open was $291.11.
- Constellation and Google said on 6 October that a 20-year power purchase agreement will support 890 megawatts of new capacity from uprates at 11 units on six sites in Illinois, Pennsylvania, and New Jersey. Constellation said the first uprate is expected by 2028. Google’s blog the same day said the 890 megawatts are to be added before the end of 2032.
- Constellation said the package represents more than $4.3 billion of new investment by Constellation, sustains roughly 4,400 existing jobs, and creates about 7,200 construction jobs. The company account on X repeated the “$4.3B+” figure that morning.
- The same release adds a 15-year supply agreement for 2,700 megawatts so existing assets keep delivering energy and capacity to PJM, plus a five-year Google Cloud and Gemini Enterprise agreement. No price per megawatt-hour is stated. The sum of 890 and 2,700 is 3,590 megawatts.
- Vistra closed Tuesday at $160.50, up 10.77 percent from $144.89. Talen closed at $373.11, up 12.43 percent from $331.87. Both are Nasdaq official closes for 6 October 2026. Neither firm is a counterparty in the Google release.
- Alphabet Class A (GOOGL) closed at $347.68, up 0.35 percent from $346.47, on volume below its prior 20-session average. Nasdaq, 6 October 2026.
- On 6 October 2025 the same Nasdaq history shows Constellation at $364.10, Vistra at $200.41, and Talen at $430.43. Tuesday’s rally left all three below those year-ago closes.
- An SEC full-text search for a Constellation 8-K filed from 5 October through 7 October 2026 that mentions Google returned no hits. The release does not name the 11 units.
What moved, and why the obvious reading is incomplete
Constellation opened at $291.11, about 8.8 percent above Monday, and the release was already public. Google News lists the post at 10:45 GMT on 6 October, or 6:45 a.m. Eastern. CNBC’s 3.6 gigawatt story is timestamped 7:58 a.m. Eastern.
Talen closed up 12.43 percent at $373.11 and Vistra up 10.77 percent at $160.50. CNBC’s Spencer Kimball article, updated at 2:38 p.m. Eastern, said both were up more than 9 percent in sympathy. The closes ran past that line, and Talen finished ahead of the company that signed.
Alphabet Class A opened at $347.37 and closed at $347.68, up $1.21, on volume about two-thirds of its prior 20-session average. The multiple went to the seller and to two merchants that did not sign.
The same session repriced the equipment that creates the load. FinanceFeeds covered Marvell’s investor-day tape and Ciena’s networking move separately. Those are chips and optical gear. This is the electricity those workloads are being contracted to sit on.
A year earlier the generators were higher. On 6 October 2025 Constellation closed at $364.10, so Tuesday is still 17.5 percent lower. Vistra was $200.41 against $160.50 now, and Talen was $430.43 against $373.11. Alphabet went from $250.43 to $347.68 over that year, up 38.8 percent. The buyer compounded. The sellers of power did not.
What the company, the customer, or the analyst actually said or did
Constellation’s release, datelined Baltimore and Mountain View on 6 October 2026, says a 20-year power purchase agreement will fund equipment at 11 Constellation-owned nuclear units in Illinois, Pennsylvania, and New Jersey. The 890 megawatts are described as entirely new generation for PJM, not a reshuffle of megawatts that already exist. The same release later places the work across six nuclear sites in those three states.
Google’s blog the same day, bylined to Amanda Peterson Corio, uses six operating plants and 11 reactors. It does not say “20-year,” and it does not restate $4.3 billion. It adds the completion clock the Constellation release leaves open: before the end of 2032 the uprates are supposed to have delivered the full 890 megawatts. Constellation’s line is the first uprate, expected by 2028. A first megawatt in 2028 and a completed block in 2032 can both be true. Treating 2028 as the date the whole 890 arrives is not what either document says.
Corio’s title is not the same on the two pages. The release calls her global head of energy and power at Google. The blog byline calls her global head of data center energy. The sentences below keep the title on the page where they appear.
On the release she says: “We’re committed to meeting our growth responsibly by actively investing in clean, reliable power that brings new capacity to our nation’s grids.” The next sentence is: “Our agreement with Constellation to fund nuclear reactor uprates will strengthen the PJM grid, which serves 67 million people, all while protecting energy affordability and supporting local union jobs.” Both lines are in Constellation’s 6 October release.
Her blog standfirst is a different claim. “Our new agreement with Constellation Energy brings the total new nuclear capacity we’ve enabled for the U.S. energy system from uprates and restarts to over 1.5 GW.” That sentence is on Google’s 6 October post. The 890 megawatts are the Tuesday increment inside a larger book. The post cites earlier work, including a NextEra restart at Iowa’s Duane Arnold plant of over 600 megawatts, and it does not publish a table that adds up to 1.5 gigawatts. It also says a Department of Energy goal is 5 gigawatts of uprates and restarts by 2030, and that Google’s agreements are expected to cover nearly 25 percent of that goal by the end of the decade. Over 1.5 gigawatts is already more than a quarter of 5. The post states both lines and does not reconcile them.
Joe Dominguez, chairman, president and chief executive, says in the release: “Preserving and expanding the output of the existing nuclear fleet and developing new clean generation is critical to meeting our nation’s growing energy needs while keeping costs affordable for homes and businesses.” The next sentence in that release says the collaboration can serve as a model for privately funded infrastructure with grid-wide benefits.
The company account @ConstellationEG, at 11:30 GMT on 6 October, posted a shorter version: 890 megawatts, “equivalent to a new reactor,” backed by “$4.3B+” of private investment. That post does not mention the 2,700 megawatt leg or 2032.
The dollar figure needs the verb on the page. Constellation says the agreement “represents more than $4.3 billion of new investment by Constellation.” Google’s blog says “this financing” and does not write the number. A headline that has Google writing a $4.3 billion check is ahead of both documents.
The 2,700 megawatt leg is the easier misread. Constellation calls it a 15-year supply agreement so operating assets “continue to deliver energy and capacity to the PJM market.” CNBC’s morning story said this power “is not tied to a specific generation source,” attributing that line to Google. It is not 2,700 megawatts of new reactors. New nuclear is about a quarter of the 3,590 megawatt sum.
Two further pieces are not new reactors either. A five-year Google Cloud and Gemini Enterprise alliance covers interconnection modeling, outage scheduling, and security for plant networks, and neither side prices it. A separate framework to study new generation and storage names no site and no megawatt. The release also says Google will curtail non-critical load in grid stress, which is how Constellation invokes PJM’s “Bring Your Own Power” proposal. No tariff is quoted.
A week earlier the template was one named plant. On 30 September Constellation and Amazon announced a 20-year deal at Calvert Cliffs. The release says more than $3 billion of investment, about 190 megawatts of new capacity from 2030 to 2032, inside a contract for 690 megawatts “including the 190 megawatt uprate,” on a 1,790 megawatt plant. The Google block is larger, earlier on the first megawatt, and unnamed by site.
Nicholas Amicucci, an analyst at Evercore ISI, said in a Tuesday note that the deals are positive for other independent producers with nuclear plants that are also uprate candidates, as reported by CNBC. The same article says Evercore estimates that “economically justified” uprates could add 4 to 8 gigawatts by the mid-2030s. That range is not in the company release. It is the on-the-record reason the peers traded with the signer. One CNBC sentence says “11 nuclear plants.” Google says six plants and 11 reactors. Use the company count.
The tape and the filings
Every close below is from Nasdaq’s daily history, saved 7 October 2026. The quote page, checked while Wednesday still read pre-market, showed Tuesday’s $300.40 as the last close, “Closed at Oct 6, 2026 4:00 PM ET.”
All three lines on the chart finish under the 1 October 2025 base of 100. Tuesday is a jump at the right edge, not a new high. Constellation’s highest close in this file is $403.95 on 15 October 2025. Nasdaq’s published 52-week range, which can be an intraday extreme, is $228.63 to $412.70. Tuesday’s $300.40 is about 27 percent under the top of that range.
| Name | Tue 6 Oct 2026 | Mon 5 Oct | Change | Session high | 6 Oct 2025 close |
|---|---|---|---|---|---|
| Constellation (CEG) | $300.40 | $267.62 | +12.25% | $309.80 | $364.10 |
| Vistra (VST) | $160.50 | $144.89 | +10.77% | $162.69 | $200.41 |
| Talen (TLN) | $373.11 | $331.87 | +12.43% | $377.99 | $430.43 |
| Alphabet Class A (GOOGL) | $347.68 | $346.47 | +0.35% | $349.09 | $250.43 |
Volume shows who was in the trade. Constellation’s 13.48 million shares were roughly 4.4 times the prior 20-session average, Vistra’s 18.11 million roughly 3.3 times, Talen’s 2.82 million roughly 3.1 times, and Alphabet’s 18.72 million about 0.68 times. Vistra’s 52-week range on Nasdaq is $132.66 to $217.10, and Talen’s is $279.77 to $449.84, so neither close is a new high. Constellation’s own close on 8 September 2026 was $299.05. Tuesday, after a 12.25 percent day, landed next to a print from a month earlier. The summer low in this file is a $236.50 close on 1 July 2026.
The SEC search returned no Constellation 8-K from 5-7 October that mentions Google. No exhibit states an energy price, a capacity price, or which unit carries which share of the 890 megawatts.
Constellation’s nuclear locations page lists ten facilities in the three states named in the agreement: Braidwood, Byron, Clinton, Dresden, LaSalle, and Quad Cities in Illinois; Crane, Limerick, and Peach Bottom in Pennsylvania; and Salem in New Jersey. The agreement says six sites. The page does not mark which six, and this article does not guess. Byron is a listed Illinois plant. It is not identified as an uprate site.
The same file, for context only, shows Tuesday closes of $38.55 for Oklo, up 7.17 percent, $93.02 for Cameco, up 6.35 percent, and $153.88 for Centrus, up 8.80 percent. None of them is a party to the release.
The constraint that sits under the headline
Time is the first constraint. The megawatts are not on the grid this quarter. Constellation’s first date is 2028 and Google’s date for the full 890 is the end of 2032. The work described is turbines, steam generators, and digital controls at plants that already run. That avoids a greenfield queue. It does not avoid an equipment lead time.
Identity is the second constraint. Six sites inside a public list of ten nuclear locations in those states means some Constellation plants there are outside the uprate set. Until the company says which, Vistra and Talen can trade as substitutes. Evercore’s comment is not evidence that Google is negotiating with them this week. No comparable Tuesday release from either peer turned up in the wires used here.
Vistra’s other uprate story is a day older. On 5 October FinanceFeeds reported that the Department of Energy was preparing a roughly $4.2 billion package for three or more Vistra stations, with an announcement expected at the Perry plant, as that piece describes. It was a package being prepared, not a Google signing.
Price is the third constraint. The release does not say Google pays the $4.3 billion, and it states no energy price and no capacity price. Tuesday’s 12.25 percent is a multiple on a spread an outsider cannot audit yet.
PJM is the grid under the number. Both companies say it serves 67 million people. Utility Dive reported on 6 October that PJM is short about 6.8 gigawatts of new capacity and will delay a reliability backstop auction after a partial FERC decision on 29 September. If that shortage is right, 890 megawatts is real and still a small share of the hole. The 2,700 megawatt leg does not fill it if those megawatts were already in the market.
What happens next
The first dated test is 2028. Constellation says the first uprate is expected then. The chain is an equipment order, an outage, and acceptance of a higher licensed output, not a new plant license. If that unit slips past 2028, the cash flow Tuesday’s close capitalized moves to the right. The release does not name the unit that is supposed to be first.
The second dated test is the end of 2032, when Google’s blog says the 890 megawatts are supposed to be in. A miss would be a smaller total, not a cancelled greenfield, and it still requires the six sites to be named. They are not named in the documents reviewed here.
The third test is the peers, on a horizon CNBC attributed to Evercore on 6 October: 4 to 8 gigawatts of economically justified uprates by the mid-2030s. Vistra’s $160.50 close and Talen’s $373.11 close are a claim on that range and, for Vistra, on the federal package reported the day before. If those companies do not sign offtake, or do not get a loan with a megawatt figure attached, the Tuesday sympathy has to be earned another way or given back. That is not a price target.
This piece does not set a bull, base, or bear price for Constellation, Vistra, or Talen. No fresh 12-month target was required to describe the close. This is not financial advice.
Frequently asked questions
What did Google and Constellation agree on 6 October 2026?
Constellation’s release describes more than one contract. A 20-year power purchase agreement is meant to support 890 megawatts of new output from uprates at 11 units on six sites in Illinois, Pennsylvania, and New Jersey. A separate 15-year agreement covers 2,700 megawatts that the company says remain in the PJM market. A five-year technology agreement puts Google Cloud and Gemini Enterprise into Constellation’s operations. The price per megawatt-hour was not disclosed.
Is the 3.6 gigawatt figure all new nuclear?
No. The 890 megawatts of new uprate capacity plus the 2,700 megawatt supply agreement equal 3,590 megawatts. CNBC reported on 6 October that the companies described a 3,590 megawatt contracting figure, with new nuclear about a quarter of it. The 2,700 megawatt leg is not new steel. Constellation says it keeps existing assets delivering energy and capacity to PJM rather than taking resources off the grid.
When does the new capacity arrive?
Constellation says the first uprate is expected by 2028. Google’s blog the same day says the projects will add the 890 megawatts before the end of 2032. That is an outage-and-equipment schedule, not power in 2026. The Amazon agreement announced on 30 September, for about 190 megawatts of new capacity at Calvert Cliffs, is a different contract and is dated 2030 to 2032.
Why did Vistra and Talen rise if they did not sign?
They are not counterparties in the Google release. CNBC, updated at 2:38 p.m. Eastern on Tuesday, called the gains sympathy and said both stocks were up more than 9 percent at that hour. The official closes were larger: Vistra at $160.50, up 10.77 percent, and Talen at $373.11, up 12.43 percent. Talen’s percentage slightly exceeded Constellation’s. A separate Vistra financing story was already in the market from 5 October.
Did the companies name the reactors?
No. Both said 11 units, or reactors, at six plants in three states. Constellation’s locations page lists ten nuclear facilities in those states and does not mark which six are in the uprate. An SEC search for a Constellation 8-K from 5 October through 7 October 2026 that mentions Google returned no filing. The market did not receive a unit-level exhibit on the day of the move.
Did Alphabet’s own stock move with the deal?
Alphabet Class A closed Tuesday at $347.68, up 0.35 percent from $346.47, on volume below its recent average. The buyer of the long-dated power did not get the multiple. Constellation, Vistra, and Talen did, and all three still finished below their closes from 6 October 2025. The deal is a cost and a volume commitment for Google, and a re-rating story for the merchants.