The best returns in modern investing tend to happen behind a velvet rope.
By the time a hot company rings the opening bell, the people who funded it early have usually banked the biggest gains. You get to buy in after the easy money is gone.
SpaceX is the freshest example. The rocket maker priced its initial public offering (IPO) at $135 a share on June 11, raising $75 billion at a $1.8 trillion valuation, according to IPOScoop.
That was the largest IPO in history. For most people with a 401(k) and a brokerage app, it was also the first time they could own the stock at all.
Venture funds, pensions and wealthy accredited investors had years of access before that. Everyone else watched the valuation climb from the sidewalk.
Cathie Wood has spent 2026 trying to pry that rope open, and her newest move puts one of the fastest-growing private companies in America inside funds you can buy for the price of a single share.
Her firm, ARK Invest, has added Kalshi, the federally regulated prediction market, to three of its exchange-traded funds (ETFs). The hype is loud. The dollars involved are smaller than you might expect.
Cathie Wood bought first and announced two weeks later
ARK bought 90,024 Kalshi shares for the ARK Innovation ETF (ARKK), 25,318 for the ARK Next Generation Internet ETF (ARKW) and 11,252 for the ARK Blockchain & Fintech Innovation ETF (ARKF), all on Sept. 18, according to Benzinga, which cited ARK’s daily trade notification.
More Cathie Wood:
- Cathie Wood buys $81.5 million of surging semiconductor stock
- Cathie Wood buys $3.5 million of surging tech stock
- Cathie Wood buys $53 million of popular semiconductor stock
That’s 126,594 shares across the three funds. The trade drew little attention at the time.
Wood made it official nearly two weeks later. “We are very happy to have introduced another private company, Kalshi, to our ETF strategies,” Wood wrote on X on Oct. 1. (ARK’s Venture Fund had previously taken a stake in Kalshi’s Series E round and then joined its Series F, according to Casino.org.)
She added that Kalshi’s management team is “skating to where the prediction markets’ puck will be,” borrowing hockey legend Wayne Gretzky’s famous line.
The word “another” matters. ARK put OpenAI into ARKK, ARKW and ARKF on April 1 at an $852 billion valuation, according to Sherwood News.
Related: Prediction markets like Kalshi are booming. 79% of users say they’ve lost money
The relationship goes deeper than ownership. “Bringing prediction markets into institutional workflows is a natural next step for innovation in financial research,” Wood said in March, when ARK announced it would use Kalshi data in its research and to hedge some portfolio risks, according to Business Wire.
How Kalshi’s valuation exploded in under a year
Kalshi lets users trade contracts on real-world outcomes, from Federal Reserve decisions to football scores, and it’s regulated by the Commodity Futures Trading Commission (CFTC). Its price tag has moved faster than almost anything in private markets.
Here’s how fast that number has climbed:
- October 2025: valuation of roughly $5 billion, according to The Block.
- May 2026: $22 billion after a $1 billion Series F led by Coatue, according to The Block.
- June 2026: talks to raise money at a $40 billion valuation, the Financial Times reported.
- August 2026: advanced talks with Sequoia Capital and Wellington Management on a $750 million round at that $40 billion figure, The Information reported.
The trading activity backs up the hype. Kalshi handled $40 billion in volume in July, compared with $12.9 billion for Polymarket and Polymarket US combined, according to The Block.
That’s why ARK thinks the whole category could become enormous. The firm projects prediction markets could reach $5 trillion in annual volume within three to five years, according to Casino.org.
“Kalshi has grown from almost no market share two years ago to ~68% of weekly notional volume today,” ARK analyst Nicholas Grous wrote in that research.
What $10,000 in ARKK actually buys you of the new holding
Here’s the part the announcement doesn’t spell out. When I worked through the trade figures ARK disclosed, Kalshi’s first purchase equaled just 0.0126% of ARKK, 0.0144% of ARKW and 0.0152% of ARKF.
In plain dollars, if you own $10,000 of ARKK, about $1.26 of it went into Kalshi on that trade. The same $10,000 in ARKF carries roughly $1.52.
That’s a rounding error, not a bet-the-fund move. ARK can add more over time, so check the fund’s daily holdings file for the current weight before you buy on the Kalshi story.
Size isn’t the only wrinkle. Private shares don’t trade on an exchange, so the fund has to estimate their value instead of reading a live price, and that estimate can lag reality in either direction.
My read is that ARK is building its private sleeve slowly on purpose. A small position lets Wood tell a big story without putting much of your money at risk if Kalshi’s valuation gets marked down.
Prediction market risks the sales pitch skips past
Wood’s record cuts both ways. Bloomberg ETF analyst Eric Balchunas noted on X that ARKK is up 322% since launch, but said Wood “had right picks but didn’t let winners run,” according to Benzinga.
Kalshi carries its own baggage. Most of its activity still comes from sports, which made up 89% of prediction market volume as of June, according to Casino.org’s summary of ARK’s research.
That means the most exciting part of ARK’s thesis, economic and political contracts that rival traditional derivatives, is still mostly a forecast.
Regulators are another wild card. Kalshi has fought state-level challenges, and in June it sued Illinois in federal court over a new $15 million licensing fee and a tax on prediction market wagers, according to Capitol News Illinois.
One bad court ruling or a hostile state law could dent the volume that justifies a $40 billion price tag. You’d feel that through ARKK’s net asset value, even if only slightly at today’s weight.
Why the private-market door matters for your portfolio next
Kalshi Chief Executive Tarek Mansour has said an IPO is under consideration but would not happen this year, according to The Block.
If Kalshi lists in 2027, ARKK holders will already own a sliver bought at private-market prices. That’s the real pitch here: a side entrance into the velvet-rope phase, for the cost of one ETF share.
I’d keep one number in view, though. At current weights, you’re buying Wood’s judgment far more than you’re buying Kalshi.
If you want prediction market upside, size it the way ARK did. Keep it small enough that a markdown never touches your retirement plans.
The rope is loosening. Know exactly how wide before you step through.
Related: ARKK bleeds $313 million as investors pull out