AMPH Amphastar Pharmaceuticals Inc.

NASDAQ
$23.78

Amphastar Pharmaceuticals Inc. (AMPH) Hedge Fund Activity

This view isolates hedge funds from the broader institutional ownership shown on the Institutional tab. A pension fund tracking an index may have no view on a stock; when a hedge fund builds or exits a position, that decision can carry information. This page measures those changes. Positions as of June 30, 2026.

Based on quarterly 13F long-equity filings. Changes compare reported quarter-end positions; filings can be reported up to 45 days later and do not represent a fund's complete exposure.

Hedge fund breadth
+14.29
12 buyers / 9 sellers
BUYING
Funds compared
21
funds with comparable AMPH positions
19 current holders · 15 prior-quarter holders
Net share change
+90.4K
+721.2K added, -630.8K cut
Position activity
6 new 6 increased 7 reduced 2 exited

Most significant moves

Ranked by conviction, not size — how much of the fund's own book the position represents, how far it moved, and what kind of fund made it.

Fund Action Shares changed Change Est. value Portfolio wt. Score
Point72 Asset Management, L.P. New +55.0K — $1.1M 0.0% 61
Gotham Asset Management, LLC Quant Value New +10.1K — $204.6K 0.0% 54
Verition Fund Management Event Long/Short Sold Out -18.6K -100.0% $375.3K 0.0% 54
Jain Global Long/Short Quant New +14.2K — $286.2K 0.0% 52
MILLENNIUM MANAGEMENT LLC Reduced -339.6K -91.4% $6.9M 0.0% 51
Trexquant Investment Quant Sold Out -47.9K -100.0% $966.0K 0.0% 51
Squarepoint Ops LLC Quant Increased +50.5K +178.0% $1.0M 0.0% 50
Y-Intercept Quant New +34.7K — $700.3K 0.0% 48
Engineers Gate Quant New +30.2K — $609.3K 0.0% 48
TWO SIGMA INVESTMENTS, LP Quant Increased +110.0K +79.6% $2.2M 0.0% 48

Most significant buyers

By move score, not size.

  • Point72 Asset Management, L.P. New · +55.0K
  • Gotham Asset Management, LLC New · +10.1K
  • Jain Global New · +14.2K
  • Squarepoint Ops LLC Increased · +50.5K
  • Y-Intercept New · +34.7K

Most significant sellers

By move score, not size.

  • Verition Fund Management Sold Out · -18.6K
  • MILLENNIUM MANAGEMENT LLC Reduced · -339.6K
  • Trexquant Investment Sold Out · -47.9K
  • CITADEL ADVISORS LLC Reduced · -49.3K
  • Voloridge Investment Management Reduced · -120.3K

Hedge fund positions

Fund Tier Shares Previous Change Change % Portfolio wt. Action Score
Point72 Asset Management, L.P. 1 55.0K 0 +55.0K — 0.0% New 61
Gotham Asset Management, LLC 2 10.1K 0 +10.1K — 0.0% New 54
Verition Fund Management 2 0 18.6K -18.6K -100.0% 0.0% Sold Out 54
Jain Global 3 14.2K 0 +14.2K — 0.0% New 52
MILLENNIUM MANAGEMENT LLC 2 31.8K 371.4K -339.6K -91.4% 0.0% Reduced 51
Trexquant Investment 3 0 47.9K -47.9K -100.0% 0.0% Sold Out 51
Squarepoint Ops LLC 2 78.8K 28.3K +50.5K +178.0% 0.0% Increased 50
Y-Intercept 4 34.7K 0 +34.7K — 0.0% New 48
Engineers Gate 4 30.2K 0 +30.2K — 0.0% New 48
TWO SIGMA INVESTMENTS, LP 2 248.1K 138.1K +110.0K +79.6% 0.0% Increased 48
AQR Capital Management 3 208.7K 78.8K +129.9K +164.9% 0.0% Increased 47
CITADEL ADVISORS LLC 1 16.2K 65.5K -49.3K -75.2% 0.0% Reduced 46
Quantbot Technologies 4 1.9K 0 +1.9K — 0.0% New 45
Brevan Howard Capital Management 3 34.2K 11.6K +22.6K +194.5% 0.0% Increased 43
Voloridge Investment Management 2 50.9K 171.2K -120.3K -70.3% 0.0% Reduced 42
D. E. Shaw & Co., Inc. 1 887.0K 665.5K +221.5K +33.3% 0.0% Increased 37
Man Group 3 17.3K 37.3K -19.9K -53.5% 0.0% Reduced 34
RENAISSANCE TECHNOLOGIES LLC 1 525.1K 553.9K -28.8K -5.2% 0.0% Reduced 29
Quadrature Capital 3 24.4K 30.6K -6.1K -20.1% 0.0% Reduced 27
MARSHALL WACE, LLP 2 1.1M 1.0M +40.7K +4.0% 0.0% Increased 26
Magnetar Capital 2 10.9K 11.2K -329 -2.9% 0.0% Reduced 24

Every fund above opens. Subscribers can see any manager's whole portfolio — every position, its weight, and what they bought, trimmed and exited last quarter.

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Hedge funds are identified from their 13F filings, which are due 45 days after quarter end and cover long U.S.-listed equity positions only. A fund's short book never appears, so a reduced position can mean a changed view or a changed hedge — the filing doesn't say which.