What is the StonkWhisper Whisper Index?

The Whisper Index is StonkWhisper's proprietary market sentiment score (0–90) that aggregates retail investor discussion velocity, volume, and sentiment across Reddit, StockTwits, and other social platforms for 500+ U.S. equities in real time.

What is dark pool trading and why does it matter for stock analysis?

Dark pools are off-exchange trading venues where large institutional orders execute away from public markets. StonkWhisper tracks FINRA-reported dark pool volume to identify unusual institutional accumulation or distribution that may precede significant price moves.

How does StonkWhisper track congressional stock trades?

The STOCK Act requires U.S. Congress members to disclose personal stock trades within 45 days. StonkWhisper monitors these mandatory disclosures in near real-time, surfacing trades by legislators who may have non-public information advantages.

American Century increased ON position by 788,838 shares

Mar 28, 2026Last updated Apr 27, 2026

This StonkWhisper whale intelligence report documents significant institutional position changes in $ON based on SEC 13F filings and block-level trading data. Quarterly 13F disclosures are required for institutional investment managers with at least $100 million in qualifying assets under management. These filings reveal long positions in U.S. equities held as of quarter end. Material changes in institutional positioning — particularly from concentrated funds with a history of high-conviction bets — are tracked by StonkWhisper as leading indicators of institutional thesis formation or exit.

AMERICAN CENTURY COMPANIES INC AUM: $199.0B INCREASED

AUM: $199.0B · 2,811 holdings · Period: 2025-12-31

+788,838 Share Change

1,555,711 Current Shares

$84.2B Current Value

0.04% Portfolio %

+102.9% Change %

Position Change Detail

Issuer ON SEMICONDUCTOR CORP

Ticker ON

Shares 766,873 → 1,555,711 +788,838

Value $37.8B → $84.2B

Portfolio Weight 0.04%

Change Type Increased

Period of Report 2025-12-31

Other American Century Positions This Period

Ticker	Issuer	Change Type	Share Change	Value
KOS	KOSMOS ENERGY LTD	Decreased	19,075,012	$10.3B
NFLX	NETFLIX INC	Increased	+15,804,792	$1642.0B
KVUE	KENVUE INC	Decreased	10,309,137	$461.2B
T	AT&T INC	Decreased	6,329,511	$98.5B
FNB	F N B CORP	Decreased	5,985,954	$42.8B
GFL	GFL ENVIRONMENTAL INC	Decreased	5,025,075	$42.9B
VICI	VICI PPTYS INC	Decreased	4,649,026	$68.4B
MARA	MARA HOLDINGS INC	Decreased	4,372,799	$2.2B
UAA	UNDER ARMOUR INC	Decreased	3,552,342	$2.3B
APH	AMPHENOL CORP NEW	Increased	+3,437,013	$788.3B

Other Whales Moving ON This Period

Manager	Change Type	Share Change
Two Sigma	Decreased	3,731,451
WorldQuant	Decreased	3,014,718
Millennium	Decreased	1,597,198
Tudor	Decreased	1,394,200
Renaissance Tech	Decreased	1,058,836
Duquesne	New	+536,260
Marshall Wace	Increased	+425,415
Citadel	Decreased	385,900
State Street	Decreased	310,343
Gotham Asset	Increased	+267,130

View all sentiment, news, and whale activity for ON (ON SEMICONDUCTOR CORP).

Track American Century and other whale moves in real time on The Wire →

Get alerts when new 13F filings drop — Go Pro →

Data sourced from SEC 13F institutional holdings filings. This page does not constitute financial advice. StonkWhisper presents public records — it does not verify or guarantee the accuracy of institutional filings. 13F filings are reported quarterly and may lag actual positions.

Last updated: April 27, 2026 at 06:02 UTC