Ciena jumps 14% as AI infrastructure names lead Monday's session

As seen on the 24/7 Wall St. homepage on October 6, 2026.

Biggest movers · At the close 4:10pm ET

Gainers

CIENCiena$445.37+14.3%
CEGConstellation Energy$300.52+12.3%
FNFabrinet$488.18+7.6%
NBISNebius Group$250.1+7.5%
ALABAstera Labs$388.9+7.3%

Losers

TEMTempus AI$71.68-14.2%
STXSeagate Technology$806.34-9.1%
MRNAModerna$187.05-8.0%
APPSDigital Turbine$10.48-6.6%
SKHYSK hynix Inc.$182.3-6.5%

Nearly 29 points of spread separated the top and bottom of the board at Monday's close, with Ciena up 14.29% to $445.37 and Tempus AI down 14.21% to $71.68. Four of the five leaders sit in AI infrastructure names.

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Ciena closed up 14.29%, the session's standout mover, confirming the optical networking name's tight connection to AI buildout spending. Constellation Energy followed, keeping the power sector's AI data-center narrative firmly in play.

Fabrinet, Nebius Group and Astera Labs all advanced behind them. Four of the five top gainers sit squarely in AI infrastructure, a clustering that points to something broader than single-stock news driving the day.

Tempus AI fell 14.21%, matching Ciena's gain almost point for point across the session's best and worst performers. Seagate Technology and Moderna also declined, giving the losers' column a mix of healthcare and storage hardware that sat well outside the day's winning theme.

Digital Turbine and SK hynix rounded out the five worst performers. The breadth of the declines across sectors suggests Monday's rotation had conviction: capital moved toward AI infrastructure with enough force to leave most everything else behind.

Sources

Mentioned: CIEN, CEG, FN, NBIS, ALAB, TEM, STX, MRNA

Related Market Updates

CIEN Ciena

After-hours

5:20pm ET

$443.84

+13.22% open $392.01

A 13.22% jump to $443.84 adds roughly $8 billion of market value to a $62.9 billion optical networking name in a single session. Moves that big are rare at this scale, and the $392.01 open is now the level to watch.

TEM Tempus AI

After-hours

5:00pm ET

$71.98

-15.32% open $85.00

A 15.3% slide to $71.98 wipes roughly $2 billion off a $12.6 billion AI diagnostics name in a single session. Moves this big reset the whole trading range, so watch where it opens next.

CIEN Ciena

Regular session

1:00pm ET

$433.50

+10.58% open $392.01

A 10.58% intraday jump to $433.50 adds roughly $6 billion to a $61.5 billion optical networking name in a single session. Moves this size are rare here, and the $392.01 open is now the level to watch if it fades.

TEM Tempus AI

Regular session

12:40pm ET

$74.22

-12.69% open $85.00

A 12.7% intraday slide to $74.22 strips roughly an eighth off a $13 billion market cap in a single session. Whether the $85 open gets reclaimed is the level to keep an eye on.

Biggest movers · On the open 9:51am ET

Gainers

CEGConstellation Energy$300+12.1%
SMRNuScale Power$8.27+7.7%
MRVLMarvell Technology$288.1+6.2%
AAOIApplied Optoelectronics$128.77+5.9%
ALABAstera Labs$381.06+5.2%

Losers

STXSeagate Technology$831.22-6.3%
SKHYSK hynix Inc.$188.84-3.2%
IQiQIYI$1-2.4%
SNDKSanDisk$1,675-1.7%
MUMicron Technology$1,046.76-1.6%

Constellation Energy opened 12.1% higher at $300, the biggest move across 385 priority names, with NuScale Power close behind. Storage is on the other side of the ledger: Seagate down 6.3%, SanDisk and Micron also lower.

Biggest movers · At the close Oct 5, 4:10pm ET

Gainers

PBR-APetrobras$22.12+12.8%
PBRPetrobras$24.17+11.6%
MELIMercadoLibre$1,864.06+9.9%
TEMTempus AI$83.63+9.1%
FUTUFutu Holdings$110.05+7.7%

Losers

OPENOpendoor Technologies$2.33-4.7%
NBISNebius Group$232.87-4.1%
BMYBristol Myers Squibb$58.81-3.8%
NOKNokia$10.22-3.6%
GLWCorning$158.53-3.5%

Both Petrobras lines closed double digits higher, the only names in a 383-stock board to do it. MercadoLibre and Tempus AI each added more than 9%, while the worst loser gave up under 5%, so the upside skew was lopsided.

New insider tie · Form 3 Juan Andres

Oct 4, 8:00pm ET

Now Chief Operating Officer at Moderna, Inc.

Moderna put manufacturing veteran Juan Andres back in an operating seat as Jerh Collins retires, and the market read it as a launch-readiness move: the stock rose 5.71% on Oct. 5. For an $81.1 billion vaccine maker whose next act depends on getting new products out the door, who runs operations is the whole story.

52-week highs Oct 2, 6:00pm ET

19 stocks hit new 52-week highs this week

HPEHewlett Packard Enterprise$69.33+9.2%
ASXASE Technology Holding$47.45+5.0%
AMCAMC Entertainment$2.77+4.4%
MRNAModerna$190.01+4.4%
SSentinelOne$25.06+4.0%
LITELumentum$1,085.42+3.1%
KEYSKeysight Technologies$384.64+3.0%
CRWDCrowdStrike$270.04+2.9%
RBRKRubrik$118.58+2.6%
PANWPalo Alto Networks$403.24+1.8%

Nineteen stocks cleared fresh 52-week highs this week, and Hewlett Packard Enterprise led the pack by topping its prior peak by 9.2% at $69.33. ASE Technology, AMC, Moderna and a cluster of security names including CrowdStrike and Palo Alto Networks also broke out.

Biggest movers · At the close Oct 2, 4:10pm ET

Gainers

TERTeradyne$448.96+8.0%
AAOIApplied Optoelectronics$115.66+7.8%
SPCXSpaceX$159.36+7.6%
HPEHewlett Packard Enterprise$69.49+7.6%
ONON Semiconductor$84.8+5.9%

Losers

WDCWestern Digital$415.97-10.1%
STXSeagate Technology$851.39-10.0%
ACNAccenture$199.29-6.1%
APPAppLovin$268.89-4.4%
SOUNSoundHound AI$5.8-4.2%

The storage names took the worst of Friday's close, with Western Digital down 10.07% and Seagate off 9.96%. Teradyne led the whole 379-name board at +7.98%.

Biggest movers · On the open Oct 2, 9:50am ET

Gainers

ONON Semiconductor$85.07+6.2%
HOODRobinhood$118.02+6.2%
MARAMarathon Digital$11.9+6.2%
BEBloom Energy$293.61+5.8%
MSTRMicroStrategy$169.41+5.5%

Losers

STXSeagate Technology$805.97-14.8%
WDCWestern Digital$415.36-10.2%
LNGCheniere Energy$260.59-4.3%
APPAppLovin$270.73-3.8%
SNDKSanDisk$1,727.07-3.4%

Storage names are taking the brunt of the open, with Seagate down 14.8%. On the other side, ON Semiconductor leads the gainers, leaving the spread across this stock universe at roughly 21 points in a single session.

PODCAST Mad Money w/ Jim Cramer Jim Cramer · 44 min

Oct 1, 7:13pm ET

Mad Money w/ Jim Cramer 10/1/26

Cramer still buys Palantir at $190 after the stock gained 60% in Q3 and stalled short of his $250 target
Salesforce, up 46.5%, called the better SaaS-apocalypse rebound than Veeva at 30 times earnings
Caterpillar's 24% Q3 profit taking framed as a buying chance on data center engine demand
IBM, down 22% on its miss, gets the wait-a-quarter rule; Home Depot stays hostage to rates

Cramer wants to add software as the bounce-back trade and the beaten-down industrial names tied to data center power. He also warns that rising rates are the real threat heading into earnings season in a couple of weeks.