ARK Invest's funds shifted again this week, adding to Rocket Lab (RKLB) and Block (XYZ) while trimming Palantir (PLTR) and Tempus AI (TEM), according to a September 7 recap of daily trade files. Here is how those disclosures actually work, how to follow high-profile funds without guessing, and how to see where your own holdings in these names sit against ARK's weightings.
What did ARK actually buy and sell this week?
ARK Invest's actively managed funds added shares of Rocket Lab (RKLB) and Block (XYZ) and reduced positions in Palantir (PLTR) and Tempus AI (TEM) across the week ending September 7, based on the daily trade emails ARK publishes after each session. These are disclosed changes, not predictions, and they cover only the four flagship names in this recap.
The headline movements broke down like this across the disclosed files:
- Rocket Lab (RKLB): shares bought, adding to ARK's space and launch exposure inside ARKX and ARKK.
- Block (XYZ): shares bought, rebuilding a fintech and Bitcoin-adjacent position that ARK has traded around for years.
- Palantir (PLTR): shares sold, trimming a large winner after a strong run.
- Tempus AI (TEM): shares sold, reducing a smaller healthcare-AI holding.
What the files do not tell you is why. ARK publishes the what and the how many, never the reasoning behind a single day's trade.
Why does ARK disclose its trades every day?
ARK discloses trades daily because it runs actively managed exchange-traded funds, and its firm has chosen radical transparency as a differentiator. Most active managers report holdings quarterly through SEC Form 13F, which arrives up to 45 days after quarter-end. ARK instead emails a same-day list of buys and sells for its active ETFs.
What the daily file does and does not contain
The daily file is a fund-level snapshot, not a personal roadmap. It answers a narrow set of questions and stays silent on the rest.
- It shows: ticker, fund, direction (buy or sell), and share count for that day.
- It shows: the resulting weight of a name once you cross-reference the full holdings file.
- It does not show: the price ARK paid, the reasoning, or what happens tomorrow.
- It does not show: anything about whether the move fits your goals, risk, or time horizon.
That last point matters. A fund buying RKLB tells you what a fund did, not what any individual holder should do.
How can you track when high-profile funds change positions?
You can track fund position changes through three main sources, each with a different lag and level of detail. Knowing the lag is the whole game, because a trade you read about in a 13F may be six weeks stale.
| Source | Who uses it | Typical lag |
|---|---|---|
| Daily trade emails | ARK active ETFs | Same day, after close |
| SEC Form 13F | Managers over $100M | Up to 45 days |
| ETF holdings files | Most ETF issuers | 1 day to quarterly |
Steps to follow a fund without guessing
Following a fund cleanly comes down to separating the fund's data from your own reactions. A repeatable routine keeps the two apart.
- Pick the primary source, not a screenshot of it. For ARK, that is the daily trade file, not a secondhand post.
- Log the four data points: ticker, direction, share count, and date.
- Cross-reference the full holdings file to see the name's weight inside the fund.
- Compare against your own book so you know your exposure before you form any view.
That fourth step is where most people stall, because their holdings live in a broker app, a spreadsheet, and their memory all at once. Pulling them together is exactly the problem a tracker solves, and our comparison of portfolio trackers versus spreadsheets walks through why manual sheets tend to drift out of date.
How do you compare your holdings against ARK's weightings?
You compare your holdings against ARK's weightings by converting both to percentages of their respective totals, then lining up the same tickers side by side. ARK might hold RKLB at roughly 2 to 3 percent of ARKK on a given day; your own RKLB stake could be a fraction of that or far larger relative to your book.
Weight, not share count, is the honest comparison. A fund holding one million shares of PLTR and you holding 40 shares is meaningless until both are expressed as a share of the whole.
A quick worked example
Say your portfolio is worth $50,000 and you hold $1,500 of Block (XYZ). That is a 3 percent weight. If XYZ sits at around 4 percent of a given ARK fund, your relative exposure is broadly comparable, which is a fact about positioning, not a suggestion to change anything.
- Your weight: position value divided by total portfolio value.
- Fund weight: taken from the fund's published holdings file.
- The gap: the difference between the two, useful context and nothing more.
PortfolioTrackr handles this by showing each position as a live percentage of your total, so lining up your XYZ or PLTR weight against a public fund figure is arithmetic you can do in seconds rather than a spreadsheet rebuild.
What does a PLTR or TEM trim mechanically mean for a holder?
A fund trimming Palantir (PLTR) or Tempus AI (TEM) mechanically means that fund reduced its share count and freed up cash or capacity for other names. It does not mechanically mean the stock will fall, and it says nothing about your cost basis, your holding period, or your reasons for owning it.
Here is what is knowable versus unknowable after a trim:
- Knowable: the fund now holds fewer shares of PLTR and TEM than it did the prior day.
- Knowable: the freed capacity went somewhere, in this case partly into RKLB and XYZ.
- Unknowable: whether ARK is early, late, or wrong.
- Unknowable: anything specific to your account.
What a holder can check, rather than guess, is concrete: your current weight in each name, your unrealized gain or loss, and whether you have an alert set at a level that matters to you. Checking your own numbers is grounded; reacting to someone else's trade is not.
How can PortfolioTrackr help you monitor these names?
PortfolioTrackr lets you monitor RKLB, XYZ, PLTR, and TEM alongside every other holding in one view, whether you entered them manually, by voice, from a CSV, or by connecting a broker. A portfolio tracker is a tool that consolidates all your positions across accounts and asset classes so you see true weight, performance, and exposure in one place.
Connecting is optional, but useful
Connecting a broker is entirely optional here. Manual entry, voice, text, CSV, and broker screenshots all work on every plan, so you can track these four tickers today without linking anything. If you do connect, PortfolioTrackr bridges to 35 brokers through SnapTrade plus three direct integrations with Alpaca, Bybit, and Interactive Brokers. Our guide on how to connect a brokerage account to a portfolio tracker covers the setup either way.
Alerts on the levels you care about
You can set price alerts on any position, and Pro and Lifetime plans add watchlist alerts on levels for names you do not yet hold. Every position and every watchlist level is checked once a minute, around the clock, so you hear within a minute of your level being reached.
- Position alerts: available on your existing RKLB, XYZ, PLTR, or TEM holdings.
- Watchlist alerts: a Pro and Lifetime feature for names on your radar.
- Status reporting: PortfolioTrackr reports where a price sits against your own targets, for example still below target or Target 1 reached, and never tells you to buy or sell.
The tool coverage spans 95 stock exchanges and 67 display currencies, so a US name like PLTR and a frontier-listed stock sit in the same dashboard. For a wider view of what different trackers offer, our 2026 portfolio tracker comparison lays out the differences with real data.
The bottom line
ARK's week of buying RKLB and XYZ and trimming PLTR and TEM is a set of disclosed facts, not a signal about your money. The useful response is to read the primary source, note the lag, and then look inward at your own weights, gains, and alert levels.
Track the names that matter to you, express every position as a percentage of your total, and let status reporting tell you when a price hits a level you chose. What you decide from there is yours, and no fund's daily trade file changes that.
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Frequently asked questions
Where can I see ARK's daily trades for free?
ARK Invest publishes a same-day trade file for its actively managed ETFs after each market close, distributed by email and on its site. It lists ticker, fund, direction, and share count. It does not include the price paid or any reasoning behind the trade.
How often do most funds disclose their holdings?
Most institutional managers over $100 million disclose holdings quarterly through SEC Form 13F, filed up to 45 days after quarter-end. That means a 13F trade you read about could be six weeks old. ARK is unusual in publishing daily trades for its active ETFs.
How do I compare my stock weight to a fund's weight?
Divide your position value by your total portfolio value to get your weight as a percentage, then compare that to the fund's published holdings percentage for the same ticker. Comparing share counts is meaningless; only percentage weights make the exposure comparable.
Can PortfolioTrackr track RKLB, XYZ, PLTR, and TEM together?
Yes. PortfolioTrackr shows RKLB, XYZ, PLTR, TEM and every other holding in one dashboard with live percentage weights. You can add them manually, by voice, text, CSV, or by connecting a broker, and set price alerts checked once a minute on any position.
Does a fund selling a stock mean I should sell too?
No. A fund trimming a stock only means that fund reduced its share count on that day. It says nothing about your cost basis, time horizon, or goals. PortfolioTrackr reports status against your own targets and does not give buy or sell advice.