Cathie Wood’s ARK Bought 154,521 Tempus AI Shares Days Before Earnings

Key Takeaways

• On Friday 30 October 2026, ARK Invest bought 154,521 Tempus AI (NASDAQ: TEM) shares in total: 93,407 through the ARK Innovation ETF (ARKK) and 61,114 through the ARK Genomic Revolution ETF (ARKG).
• The dollar value of the purchase is reported inconsistently: TheStreet’s headline says $11.2 million, while its own article body says the shares were “worth about $12.0 million based on the transaction price.” The share count is the solid fact.
• The buy came after two days of selling: ARKK sold 58,371 Tempus shares on 28 October and 7,625 on 29 October, a combined 65,996 shares, before buying back on 30 October.
• Tempus reported third-quarter 2026 results on Monday 2 November, the next trading day after the purchase: revenue of $411.5 million, up 23% year over year, with oncology volume up 32% and Data & Applications revenue up 33%.
• Tempus shares fell 7.2% on the day of the purchase, jumped 8.67% to close at $78.48 on earnings day, then fell on each of the next three sessions, closing at $70.43 on 5 November.
• ARK sold Tempus again after earnings, including 30,035 shares on 2 November and 75,243 shares through ARKK on 4 November, according to reported trades and an unofficial ARK trades tracker.

What happened on 30 October

On Friday 30 October 2026, Cathie Wood’s ARK Invest bought Tempus AI shares across two of its exchange-traded funds. The ARK Innovation ETF (ARKK) bought 93,407 shares, and the ARK Genomic Revolution ETF (ARKG) bought 61,114 shares, for a combined total of 154,521 shares. The trade was reported by TheStreet, which put the value at $11.2 million in its headline but said in the body of the same article that the shares were “worth about $12.0 million based on the transaction price.” Because the two figures in the same report do not agree, this article treats the share count of 154,521 as the reliable fact and flags the dollar value as conflicting rather than settling on one number.

Tempus AI, Inc. (NASDAQ: TEM) is a Chicago-based health-technology company founded in 2015 by Eric Lefkofsky. It uses artificial intelligence and data to advance precision medicine, with genome sequencing and diagnostics mainly for oncology, plus work in cardiology, radiology and pharmacogenomics for depression. Tempus describes itself as “a technology company leading the adoption of AI to advance precision medicine,” in the words of its 2 November 2026 press release. The business has two parts. In the third quarter of 2026, Diagnostics contributed $303.5 million of revenue, up 20% year over year, and Data & Applications contributed $108.1 million, up 33% year over year. Diagnostics is genomic and oncology testing. Data & Applications licenses de-identified multimodal data, models and AI tools to pharmaceutical and biotechnology companies for drug development.

Search interest in the trade rose sharply. Google Trends data for the seven days around the story showed “cathie wood tempus ai stock purchase” rising by 3,450% and “tempus ai stock” rising by 200%. Those figures describe an observed rise in search interest over seven days, not a volume of searches, and they should be read that way: more people were looking up the trade and the stock, which says something about attention, not about the value of either company.

A buy after selling, not a first position

The 30 October purchase was not ARK opening a new position in Tempus. It was a buy that followed two days of selling in the same fund. ARKK sold 58,371 Tempus shares on Wednesday 28 October 2026 and a further 7,625 shares on Thursday 29 October, a combined 65,996 shares sold in the two sessions immediately before the purchase. On Friday, ARK bought back more shares than it had sold in those two days, and it did so across two funds rather than one.

That context matters, because a single day’s trade in an actively managed ETF can look very different depending on what happened around it. Tempus had, in TheStreet’s words, “long been one of the top 10 holdings” of ARKK. As of 30 October 2026, it ranked third in ARKK at $415.8 million, or 5.77% of the fund, behind Tesla at $776.1 million (10.77%) and SpaceX at $443.6 million (6.15%). In other words, the purchase added to a position ARK already held at scale, in a fund where Tempus was already one of the largest holdings.

No explanation from ARK for the trades was reported. ARK’s daily trades are disclosed, but the reasoning behind them is not, and this article does not invent one. What can be said is what the record shows: selling on Wednesday and Thursday, buying on Friday, in larger size than the sales, just before a scheduled earnings report.

Why the timing drew attention

The purchase came immediately before Tempus reported third-quarter 2026 results on Monday 2 November 2026. That timing is the main reason the trade attracted attention, and TheStreet labelled the obvious reading as speculation rather than fact, writing that “Wood’s purchase could also be a bet on earnings.” That is a guess about motive, clearly labelled as such by the outlet that printed it, and it is not an ARK statement. No statement from ARK explaining the trade has been reported.

There was also a pattern in Tempus’s recent earnings history that made the timing interesting. TheStreet reported on 1 November 2026 that Tempus had beaten estimates in each of its last four reports before this one, but that its stock had fallen on all four earnings days. A company can beat expectations and still fall on the day, and Tempus had done exactly that four times in a row. That history does not predict what would happen on 2 November, but it does explain why traders were watching the reaction closely rather than assuming a good report would mean a higher share price.

The broader market context added to the attention. The last week of October 2026 was a volatile one for AI-related shares, with sharp falls across several well-known names. Our coverage of that selloff, AI Bubble Fears Surge: What the Data Actually Shows, explains why investors were repricing risk at the time. Related reading: our breakdown of Anthropic’s IPO filing goes through what that filing disclosed. A large, visible buy by a well-known investor in the middle of that volatility was always going to be noticed, and the earnings report due the next trading day gave it a natural focal point.

What Tempus reported on 2 November

Tempus reported its third-quarter 2026 results on Monday 2 November 2026, and the numbers were strong on the headline measures. Total revenue was $411.5 million, up 23% year over year. Oncology volume rose 32%, and Data & Applications revenue rose 33%, the two growth figures the company led with. Adjusted EBITDA was $25.6 million, compared with $1.5 million in the third quarter of 2025. The net loss narrowed to $(14.9) million, from $(80.0) million a year earlier. Cash and marketable securities stood at $854.4 million.

The company’s founder and chief executive, Eric Lefkofsky, said in the release: “Q3 was another record quarter, as we delivered $411.5 million of revenue, led by accelerating unit growth of 32% in our oncology business and increasing momentum of 33% revenue growth in Data & Applications.”

Tempus also raised its full-year 2026 revenue guidance, to $1.60–$1.605 billion, implying about 25% annual growth, and said it expected full-year Adjusted EBITDA of about $65 million. The guidance raise deserves a closer look, because it was smaller than the headline suggests. The new range raised only the lower end, from $1.595 billion, so the midpoint of the range moved up by just $2.5 million. A raised range is still a raise, but the size of the move matters, and in this case it was modest.

The same release carried several other items. Tempus announced a multi-year collaboration with Merck and Moderna on an individualized neoantigen therapy. In October it agreed a data-licensing collaboration with Bristol Myers Squibb worth up to $137.5 million over five years paid directly to BMS, plus $55 million over five years for BMS and Pathos data in Alzheimer’s disease and dementia, taking total data-licensing bookings to more than $550 million year to date. The company received regulatory clearance for its pending acquisition of Personalis (PSNL), with a shareholder vote planned for 30 November 2026. It also received two FDA 510(k) clearances, for Tempus ECG-PH and Tempus ECG-MR.

Those details help explain why the Data & Applications segment draws attention. It is the smaller of the two segments by revenue, at $108.1 million against $303.5 million for Diagnostics, but it grew faster, at 33% against 20%, and the data-licensing deals announced in the quarter suggest the company is building a second revenue stream on top of its testing business. Whether that stream can keep growing at that pace is a question for future quarters, not something this quarter’s results settle on their own.

How the stock moved around the purchase

The share price moved sharply in both directions in the days around the trade. On Friday 30 October, the day of the purchase, Tempus shares fell 7.2%. That means ARK bought into a falling stock, at least on that day’s trading. On Monday 2 November, earnings day, the shares closed at $78.48, up 8.67%, with an intraday high of $80.62, which was 11.6% above Friday’s $72.22 close. The intraday high is not a closing price, and the distinction matters: the stock touched $80.62 during the session but finished the day at $78.48.

The rally did not hold through the rest of the week. On Tuesday 3 November, the shares closed at $77.80, down $0.68, or 0.87%. On Wednesday 4 November, they closed at $75.61, down 2.81%. On Thursday 5 November, they closed at $70.43, down $5.18, or 6.85%. By the close on 5 November, the stock was below where it had closed on the Friday of the purchase, despite the strong earnings-day jump in between.

Analysts moved after the results. Needham raised its price target on Tempus to $89 from $75 on 2 November. On 3 November, Jefferies upgraded the stock to Hold with a $70 target, and BTIG raised its target to $100. Those moves are reported analyst actions, not predictions made by this article, and they point in different directions: one firm raising its target, another upgrading to Hold, a third raising its target to a level above the others. The disagreement among analysts is itself part of the story.

What ARK did next

ARK did not hold still after the purchase. On Monday 2 November, after earnings, ARK sold 30,035 Tempus shares, according to a report by Nacionale citing Investing.com. On Wednesday 4 November, ARKK sold 75,243 Tempus shares, according to the ARK Invest Daily Trades Tracker, an unofficial tracker of ARK’s disclosed trades. As of 6 November 2026, that tracker listed ARK as holding 7,538,498 Tempus shares across ARKG and ARKK, with a market value of $530,936,414.14.

The sequence is now a full round trip in miniature: selling on 28 and 29 October, buying on 30 October, selling again on 2 and 4 November. That pattern is consistent with active trading around an event, but it is also consistent with routine position management, and the available reporting does not say which it was. What it does establish is that the 30 October purchase was not a one-way commitment. ARK added shares before earnings and reduced the position in the days after, while still holding more than 7.5 million shares in total.

It is worth being careful about the sources here. The 2 November sale is reported by Nacionale citing Investing.com. The 4 November sale and the 6 November holding figure come from the ARK Invest Daily Trades Tracker, which is an unofficial tracker, not an ARK publication. The figures are reported as the tracker lists them, and readers who want the primary record should check ARK’s own daily trade disclosures.

The bottom line

The facts of this story are narrower than the headlines suggest, and they are worth keeping separate from the speculation around them. ARK bought 154,521 Tempus shares on 30 October 2026, after selling 65,996 shares in the two prior sessions, and Tempus was already a top-three holding in ARKK. The purchase came one trading day before third-quarter results that beat expectations on revenue growth, with $411.5 million in revenue, up 23% year over year, and a raised full-year guidance range whose midpoint moved up by only $2.5 million. The stock fell on the purchase day, jumped on earnings day, and then fell for three straight sessions to close at $70.43 on 5 November. ARK sold shares again on 2 and 4 November.

None of that amounts to a verdict on Tempus, on ARK, or on AI in healthcare. A single fund’s trades around a single earnings report cannot settle whether a company is fairly valued, and this article makes no recommendation about the stock. What the episode does show is how closely a well-known investor’s trades are watched, how quickly a buy before earnings becomes a story, and how little of the story is actually explained by the trade itself. The trade is disclosed. The motive is not. The earnings are reported. The share price moved both ways in the same week. Those are the facts, and the rest is interpretation that readers should treat as such.

Sources: TheStreet, Cathie Wood Buys $11.2 Million of Popular AI Stock Tempus AI (TEM); Tempus, Tempus Reports Third Quarter 2026 Results; Stocktwits, TEM Stock Jumps on Upbeat Revenue, Raised Outlook; Cathie Wood’s ARK Buys Over 154K Shares Ahead of Earnings; MarketBeat, Tempus AI Surges on Earnings Beat but Can the Rally Last?