Stocks/Funds/CIK 1600133

13D Management LLC

microcap filerlong-term holderconcentrated
Quarterly 13F filings · Latest period 2026-03-31 · CIK 1600133
Assets
$64M
-43.1% YoY
Holdings
13
Lifetime alpha vs market
-6.49% annual
Average hold time
2.3 yr
median 1.0 yr

Quarterly history

Cum return +16% vs S&P +52% · α -36% lifetimeAUM $64M · peak $392MFlow $-17M (-21%)2016-062017-122019-062020-122022-062023-122025-062026-03
AUM ($B)fundS&P 500(gap = α)/ Flow in/out

Behavior signals (lifetime)

Dip response
-3.62%
trims when stocks drop
when a holding falls −10%+
Middle response
-4.57%
baseline attrition
Rally response
-6.30%
trims into rallies
when a holding rises +10%+

Top positions · 13

Ticker$ value% portYoYHold time
TWLOTwilio Inc.$8M11.9%+28.5%2.0 yr
VSATViasat, Inc.$8M11.7%+339.5%0.8 yr
ACHCAcadia Healthcare Compan$7M10.7%-22.9%0.3 yr
PSOPearson plc$6M9.3%-16.0%6.0 yr
ALVAutoliv, Inc.$6M9.1%+22.4%8.0 yr
CRLCharles River Laboratori$4M6.9%+14.6%1.0 yr
MRCYMercury Systems, Inc.$4M6.8%+69.2%4.0 yr
EXELExelixis, Inc.$4M6.7%+16.2%3.0 yr
ITGRInteger Holdings Corpora$4M6.4%-25.4%0.5 yr
ETSYEtsy, Inc.$4M5.6%+5.9%2.3 yr
$3M5.1%0.5 yr
TRIPTripadvisor, Inc.$3M5.0%-24.8%0.8 yr
WKWorkiva Inc.$3M4.8%-21.4%0.5 yr

Portfolio composition (YoY)

Industry mix
Software - Infrastructure11.9%+3.5pp$8M
Communication Equipment11.7%$8M
Medical - Care Facilities10.7%$7M
Publishing9.3%+2.7pp$6M
Auto - Parts9.1%+4.6pp$6M
Medical - Diagnostics & Research6.9%$4M
Aerospace & Defense6.8%-0.9pp$4M
Biotechnology6.7%+1.9pp$4M
Medical - Devices6.4%$4M
Specialty Retail5.6%+2.2pp$4M
Country
US76.4%-8.0pp
GB9.3%-1.7pp
SE9.1%+4.6pp
Unknown5.1%
Top 5: 52.6% · Top 10: 85.1% · Top 25: 100.0%

Winners

TickerPrev $PnLYoY %
MRCY$9M+0.01B69.2%
TWLO$6M+0.00B28.5%
ALV$5M+0.00B22.4%
EXEL$5M+0.00B16.2%
ETSY$4M+0.00B5.9%

Losers

TickerPrev $PnLYoY %
PSO$8M-0.00B-16.0%

Top buys this quarter · 1

ACHC Acadia Healthcare Company, Incnew+$7M

Top sells this quarter · 8

SWX Southwest Gas Holdings, Inc.exit$6M
WEX WEX Inc.exit$4M
BILL Bill.com Holdings, Inc.exit$3M
LW Lamb Weston Holdings, Inc.exit$3M
MRCY Mercury Systems, Inc.$3M
VSAT Viasat, Inc.$7M
EXEL Exelixis, Inc.$1M
CRL Charles River Laboratories Int$0M

Quarterly history (TTM returns)

PeriodAUM# PosReturn (1yr)SPY (1yr)Alpha (1yr)Flow
2026-03-31$64M13+13.46%+17.59%-4.13%-0.02B
2025-12-31$84M16+6.69%+17.72%-11.03%-0.02B
2025-09-30$104M18+10.05%+17.52%-7.47%-0.02B
2025-06-30$110M20+6.06%+14.94%-8.88%-0.01B
2025-03-31$113M21-6.55%+8.30%-14.85%-0.01B
2024-12-31$135M21+8.30%+24.89%-16.59%-0.01B
2024-09-30$136M22+19.99%+36.04%-16.04%-0.01B
2024-06-30$137M21+7.09%+24.49%-17.40%-0.02B
2024-03-31$164M28+17.92%+29.62%-11.71%-0.02B
2023-12-31$170M29+18.93%+26.18%-7.24%-0.02B
2023-09-30$161M28+14.60%+21.57%-6.97%-0.01B
2023-06-30$183M28+5.66%+19.42%-13.76%-0.02B
2023-03-31$197M27-6.93%-7.82%+0.88%-0.01B
2022-12-31$190M28+11.76%+7.56%+4.20%-0.01B
2022-09-30$181M30-13.63%-4.93%-8.70%-0.00B
2022-06-30$215M29-9.94%-16.11%+6.17%-0.01B