New York, Jan 5, 2026, 13:20 EST — Regular session
- Ciena shares slid about 7.8% midday, reversing an early spike to a fresh intraday high.
- The drop came as the broader U.S. market held gains, while optical peer Lumentum also fell sharply.
- Investors are weighing valuation after Ciena’s late-2025 surge, with attention turning to the next update cycle.
Ciena Corp shares were down about 7.8% at $226.75 in midday New York trading on Monday, after touching $253.30 earlier in the session and then sliding to a low of $223.61.
The move stood out against a firmer tape: the S&P 500 ETF and Nasdaq 100 ETF were both higher, while optical components maker Lumentum dropped about 7.7%, pointing to a broader unwind in parts of the AI-networking trade.
Why it matters now is valuation. In a note published Monday, Zacks Equity Research highlighted Ciena’s premium multiple — a forward price-to-earnings ratio, a valuation gauge based on expected profit — while reiterating management’s fiscal 2026 revenue outlook of $5.7 billion to $6.1 billion and pointing to roughly $5 billion in backlog, or orders not yet recognized as revenue. 1
Short positioning has also crept higher. Yahoo Finance data show about 7.31 million Ciena shares were sold short as of Dec. 15 — stock borrowed and sold by traders betting on declines — representing 8.42% of float, the shares available for public trading. 2
The stock’s sharp run into year-end left it exposed to fast reversals. Ciena’s investor relations site shows shares closed at $246.06 on Jan. 2 after hitting $248.50, a 52-week high. 3
Recent disclosures have been light. Ciena’s SEC-filings page lists a Form 144 filed on Jan. 2, a notice tied to planned sales of restricted stock, alongside late-December insider transaction reports. 4
Some valuation models circulating among retail platforms have added to the debate. Simply Wall St, using a discounted cash flow model, flags the stock as trading above its estimate of fair value — one of several frameworks investors use to stress-test expectations after big runs. 5
The bigger risk is that the market starts demanding a higher return to hold high-multiple AI-linked names. “You need a pin that pricks the bubble and it will probably come through tighter money,” said Trevor Greetham, head of multi-asset at Royal London Asset Management, in a Reuters report on inflation risks tied to heavy AI investment. 6
Technically, traders often watch the day’s extremes for clues on where buyers and sellers step in. Ciena has swung between roughly the low-$220s and low-$250s on Monday’s range, putting the $223 area in focus as near-term support and the $250 region as the next resistance. 7
