Back in late January, we wrote about how Reddit had called SanDisk early. At the time, the stock had just blown through earnings, jumped roughly 14% after-hours, and was up more than 120% in a single month. The piece argued that Reddit's chatter had picked up the move before traditional coverage caught it.

Three months later, the question worth asking is: did the signal hold up?

Short answer: yes, and then some. SanDisk just hit an all-time high of $1,079 intraday and crossed the $1,000 mark for the first time. The stock is up another ~100% since the day that article published, and roughly 2,900% over the past 12 months.

When we last covered SNDK on January 29, the stock had just closed at $539.30. That already felt like a vertical move. The story since then has been a near-doubling on top of that, pushed forward by three reinforcing tailwinds.

NAND pricing went vertical. NAND contract prices rose roughly 60% in the first quarter, with TrendForce forecasting another 70% to 75% sequential increase in Q2. SanDisk sits directly in the path of that pricing tailwind. The Q2 print confirmed the leverage: revenue of $3.025B (up 61% YoY), non-GAAP EPS of $6.20 against a $3.54 estimate, and free cash flow of $980M.

The Nasdaq-100 inclusion landed. On April 10, Nasdaq announced SNDK would join the Nasdaq-100 on April 20, replacing Atlassian. The index is tracked by more than 200 investment products with over $600B in assets globally, meaning passive funds had to buy. Forced demand, no opinion required.

Wall Street caught up. Bernstein lifted its target to $1,250. BofA raised theirs to $1,080. Jefferies took theirs from $700 to $1,000. Melius initiated coverage with a Buy and a $1,350 target. The same analysts who had a median target of $843 in mid-April were chasing higher. That's a recurring pattern when alternative data signals lead. Sell-side coverage tends to follow the move rather than anticipate it.

Reading the January piece now is a useful exercise. The whole thesis was that Reddit chatter had picked up SanDisk before traditional coverage did. What's worth showing now is just how clean the signal was, and how it kept pulsing through every leg of the rally.

For most of December 2025, SanDisk had zero Reddit mentions per day. The ticker wasn't on the retail radar at all.

That changed on January 6, when daily mentions spiked to 206, the first real signal. Three weeks before our original article. Twenty-three days before earnings. Before any analyst raised a price target. That's the window AltIndex Reddit Alerts are built to surface.

Every major leg up in the stock was preceded, or accompanied, by a fresh wave of Reddit attention:

The pattern is what mattered. Persistent mentions that stay elevated above baseline, with fresh spikes around catalysts, is the textbook signature of a stock the crowd has decided is in play. The useful information isn't whether any one Redditor is right about where the stock is going. It's that the volume of conversation, sustained over weeks, is itself the signal. That's the part you can systematize.

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AltIndex members subscribed to Reddit Stock Alerts were notified the day SNDK's mention volume broke out of its baseline in early January. The stock has doubled since.

Reddit works as a discovery channel because retail investors talk about ideas before they reach mainstream coverage. A surge in mentions usually means a catalyst, a thesis, or a setup is gaining traction with people who are paying close attention. Catching that surge early gives you time to do the work before the broader market is bidding the stock up.

It's not a free lunch. Plenty of trending tickers are momentum chases, pump-and-dump setups, or stories that don't survive a closer look. The signal tells you where to look, not what to buy. Doing the fundamental work after the alert is the part that turns attention into a real investment thesis.

This is the part where we have to be honest. The setup that made SNDK a high-conviction Reddit pick in January is not the setup today.

In January, the stock was a structurally underfollowed pure-play that the market had positioned short. Today, it's at $1,076, in the Nasdaq-100, and trading at roughly 125x earnings. Sell-side median target sits below the current price.

Memory is also a famously cyclical business. The supply shortage that drove this move will, eventually, become a supply glut. That's how the NAND cycle has always worked. The question isn't whether the cycle peaks. It's when. And once that becomes consensus, the multiple compresses fast.

For long-term investors with a position established near the Reddit signal in January, the question is risk management, not whether the original thesis worked. It worked. It's now a different stock with a different setup.

For everyone else, the more useful takeaway isn't about SNDK. It's about the next SNDK. The early January Reddit signal that flagged this move is the kind of pattern that surfaces every few months on different tickers. Tracking it systematically is what separates getting in early from reading about the move on CNBC after it's already over.

AltIndex Reddit Stock Alerts notify you when a ticker starts trending across Reddit, so you can dig in early.

That’s all for today’s special edition. We hope you got value from it. Reply and let us know if you did. 

Until next week,

— Brandon & Blake