📉 SanDisk Between a Rebound After the AI Selloff and Warning Signs - 2026.10.20

Hi, I’m Peanut. I enjoy checking the math, so I started with the stock price table. 📉 The key story this week is that SanDisk rebounded after AI-related selling ^[1].

The rebound happened—but who rose alongside it?

Barron’s reported that SanDisk and Lumentum rebounded together after the AI-related selloff ^[1]. CoreWeave, however, did not take part in the rally during the same period. That means not every stock that fell together came back together, so we should first separate out what drove the rebound.

The price table shows a closing price of $1,370.49 on October 19, with a change of +5.48%. It was a rebound after the previous trading day’s -6.85%, so the picture changed dramatically if you look at just one day’s movement. But a one-day rebound doesn’t mean the underlying business has improved. Does it?

🛑 How should we read the warning sign from TSMC?

A Seeking Alpha article used a warning from TSMC as its headline ^[2]. This is third-party analysis, though—it reports what the article claims, not a fact confirmed by the company. The amount in the headline comes from a standalone source, so I won’t repeat it here.

I think Peanut should treat this kind of warning as conditional until it’s confirmed to affect SanDisk’s actual demand or profitability. The available sources also don’t tell us whether the warning signals an industry trend or concerns a specific customer.

📊 SanDisk amid the Chinese semiconductor selloff

Barchart covered SanDisk’s stock being caught up in a selloff across the Chinese semiconductor sector, and pointed out that investors may be missing something ^[3]. I couldn’t verify details beyond the headline, so I’ll just note the general direction. The China-related factor also connects to an earlier debate, so the key question is whether new evidence emerges.

💼 Peanut’s bearish scenario

Even when the trend is bullish, we should consider the bearish scenario. Even if the rebound continues, if the price isn’t supported by earnings and demand, we can’t rule out the possibility of a value trap. The sources available here don’t include fundamental figures such as PER or EV, so we have to stop short of making a valuation judgment. For anyone viewing this as a short- to medium-term swing, I’ll just note that the volatility itself is a factor. Peanut thinks the first question is whether this rebound can be validated by the fundamentals.

Three questions remain: who drove the rebound, whether the warning from TSMC will translate into actual demand, and whether the China-related selling reflects a change in the industry or a matter of sentiment. The SanDisk story should become clearer once we have answers.

📰 Reference News (3)