ESSEX INVESTMENT MANAGEMENT CO LLC RPID — RAPID MICRO BIOSYSTEMS INC

Ownership history in ESSEX INVESTMENT MANAGEMENT CO LLC  ·  6 quarters on record

AI Ownership Summary

ESSEX INVESTMENT MANAGEMENT CO LLC reported RAPID MICRO BIOSYSTEMS INC (RPID) in 6 quarterly 13F filings from 2025 Q1 through 2026 Q2. Peak portfolio weight reached 0.32% in 2026 Q1. The latest visible filing shows RPID at 0.08% of the fund.

This page tracks quarterly shares, estimated market value, portfolio weight, filing dates, and disclosure-aligned stock prices directly from SEC EDGAR 13F filings.

What this RPID ownership page tells you

This page is designed to answer the real investor question behind a 13F filing: how meaningful was ESSEX INVESTMENT MANAGEMENT CO LLC's position in RAPID MICRO BIOSYSTEMS INC, and how did that conviction change over time? You can read the holding window, peak weight, latest reported size, disclosure timing, and quarter-by-quarter changes without piecing the story together from raw SEC rows.

Freshest filing
Latest Reported Filing
2026 Q2

RPID was reported at 0.08% of portfolio in the most recent visible filing.

High-water mark
Peak Conviction
0.32% in 2026 Q1

Peak weight helps separate a token disclosure from a real conviction holding the fund genuinely cared about.

Time in book
Holding Window
2025 Q1 to 2026 Q2

Longer holding windows often tell a very different story from short-lived tactical trades or one-quarter experiments.

Decision context
Why It Matters
Position size beats headlines

Knowing that a fund owned a stock is useful. Knowing whether it was a 0.20% placeholder or a true high-conviction position is where the signal actually starts.

RPID stock page ESSEX INVESTMENT MANAGEMENT CO LLC fund profile ESSEX INVESTMENT MANAGEMENT CO LLC full holdings
How ESSEX INVESTMENT MANAGEMENT CO LLC held RPID — position size vs. price
% of Fund (quarterly)    RPID price (quarter-end, indexed to 100)    SPY (indexed to 100)    QQQ (indexed to 100)
📋 Quarterly Holdings History 6 quarters  ▾
Quarter Action Sold % After 3M Timing Shares Change Chg % % of Fund Mkt Value Filed Price (Filed)
2026 Q2 REDUCED — — — 362,696 -521,235 -59.0% 0.08% $627K 2026-08-06 $2.08
2026 Q1 ADDED — — — 883,931 +821,605 +1318.2% 0.32% $2.0M 2026-05-11 $2.58
2025 Q4 UNCHANGED — — — 62,326 — 0% 0.03% $181K 2026-02-13 $3.91
2025 Q3 UNCHANGED — — — 62,326 — 0% 0.03% $208K 2025-11-06 $2.75
2025 Q2 REDUCED — — — 62,326 -731 -1.2% 0.04% $215K 2025-08-12 $2.68
2025 Q1 INITIATED — — — 63,057 — — 0.03% $166K 2025-05-07 $2.32

🏢 Other funds also holding RPID

As of 2026 Q2 — sorted by position size

ABG-WTT Global Life Science Capital Partners GP Ltd 3Y 37.39% Bain Capital Life Sciences Investors, LLC 3Y 7Y 0.87% Evernest Financial Advisors, LLC 0.18% ARMISTICE CAPITAL, LLC 3Y 7Y 0.07% Legato Capital Management LLC 3Y 7Y 0.02% NANO CAP NEW MILLENNIUM GROWTH FUND L P 0.02% ADVENT INTERNATIONAL, L.P. 3Y 7Y 0.0% XTX Topco Ltd 3Y 0.0% ALGERT GLOBAL LLC 3Y 7Y 0.0% RENAISSANCE TECHNOLOGIES LLC 3Y 7Y 0.0%

FAQ About ESSEX INVESTMENT MANAGEMENT CO LLC and RPID

These are the practical questions this page is built to answer before you even open the full history table.

How long has ESSEX INVESTMENT MANAGEMENT CO LLC reported owning RPID?

ESSEX INVESTMENT MANAGEMENT CO LLC reported RPID across 6 quarterly 13F filings, from 2025 Q1 through 2026 Q2.

What was the largest reported RPID position in ESSEX INVESTMENT MANAGEMENT CO LLC's portfolio?

The largest reported portfolio weight for RPID was 0.32% in 2026 Q1.

What is the latest reported RPID position on this page?

The most recent filing on this page is 2026 Q2, when ESSEX INVESTMENT MANAGEMENT CO LLC reported 362,696 shares, equal to 0.08% of portfolio, with an estimated market value of $627K.

What does the chart on this RPID ownership page compare?

The chart compares ESSEX INVESTMENT MANAGEMENT CO LLC's quarterly RPID portfolio weight with the stock's indexed share price, so you can see whether the fund was building, trimming, or holding the position as price moved.

How well did ESSEX INVESTMENT MANAGEMENT CO LLC time their RPID position?

Based on 13F filing dates vs. subsequent RPID price moves, ESSEX INVESTMENT MANAGEMENT CO LLC correctly timed 1 out of 3 reported position changes (33%). The annualised alpha on RPID relative to SPY over the holding period was +359.4%.

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