Cathie Wood trades · 15 Sep 2026

Cathie Wood tops up Ionis Pharmaceuticals Inc for $8.6M after a rough week

ARKG added on weakness rather than waiting for a bounce. The rest of the day's trades, plus ARK's scorecard against the S&P 500.

By ETFpeek Research15 Sep 2026Data: ARK daily holdings files

Cathie Wood tops up Ionis Pharmaceuticals Inc for $8.6M after a rough week

Generated from ARK's own holdings data.

Cathie Wood's ARK Invest bought an estimated $8.6M of Ionis Pharmaceuticals Inc (IONS) on 15 Sep 2026, through ARKG. It came after a 11% drop over the previous week.

When cash came into an ARK fund, every stock in it moves by the same percentage — about 0.9% that day. IONS grew 29%, so this was a choice, not plumbing.

IONS bought

$8.6M

ARKG

Stock that week

-11%

bought into the drop

ARKG this year

+84.2%

S&P 500 +14.0%

ARKG over 5 years

-31.7%

S&P 500 +85.8%

It is part of a pattern: over the last 30 days ARK is a net buyer of Ionis Pharmaceuticals Inc, $11.7M across 4 trades.

Everything ARK did on 15 Sep 2026

ARK made 22 real moves that day, once money flowing in and out of the funds is stripped out:

Stock	Funds	Est. value
TXG 10X Genomics Inc	ARKG and ARKK	−$22.6M
CRCL Circle Internet Group Inc	ARKK and ARKW	−$13.9M
GOOG Alphabet Inc	ARKK	−$13.2M
AMD Advanced Micro Devices	ARKK and ARKW	−$10.1M
IONS Ionis Pharmaceuticals IncBought after a 11% drop this week	ARKG	+$8.6M
META Meta Platforms Inc	ARKW	+$7.3M

The bigger picture: ARK's last 30 days

The 30-day picture: Nvidia Corp ($75.8M), Broadcom Inc ($61.0M), Cerebras Systems Inc ($60.9M) have taken the most new money. The biggest sales over the same period: Advanced Micro Devices ($153.9M), Palantir Technologies Inc ($73.6M), Twist Bioscience Corp ($59.6M).

Is it working?

This year ARKG is ahead of the market — +84.2% against +14.0% for the S&P 500.

Over the past month ARKG returned +7.9% to the index's +0.9%. The biggest contributors: 10X Genomics Inc (+21%, 10% of the fund), Arcturus Therapeutics Holdin (+95%, 1% of the fund), Tempus AI Inc (+15%, 7% of the fund).

Over the past year the gap is wider: ARKG returned +100.1% against +18.5% for the S&P 500, 82 points apart.

Over five years the gap is 118 points. ARKG is 52% below its all-time high from Jan 2021, having fallen as much as 84% at its worst in Apr 2025.

To date	1 month	YTD	1 year	5 years
ARKG	+7.9%	+84.2%	+100.1%	-31.7%
S&P 500 (SPY)	+0.9%	+14.0%	+18.5%	+85.8%
Nasdaq-100 (QQQ)	+4.8%	+21.5%	+25.9%	+105.3%

Track every Cathie Wood trade →Today's buys and sells, ARK vs the market, and how the six ARK funds compare. Updated every market day.

IONS in every ETF ARKG holdings

How we work this out

ARK publishes every fund's full holdings each day. We compare each day with the one before. When money flows into a fund, ARK buys more of every stock by the same percentage, so we strip that out and count only the moves beyond it as real decisions. Dollar values are estimates: shares traded × that day's price from ARK's own file.

ETFpeek is an independent research tool and is not affiliated with ARK Invest or Cathie Wood. Figures are estimates from public fund data, shown for information only — not financial advice. Past performance does not indicate future results.