Yorktown Energy Partners X, L.P.

CIK 1577919 · last filed 2024-12-18

Yorktown Energy Partners X, L.P. is a corporate insider who has filed 18 SEC Form 4 insider transactions across 5 companies since 2016. The most recent filing, for SEI, was dated May 8, 2026. Across all open-market trades the lifetime net is −$150.4M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $49.2M across reported positions.

"Disclosed insider exposure" sums this person's most-recently-reported share counts across each company they're an insider in, multiplied by the current underlying price. It is not net worth — it misses retail holdings, private investments, real estate, index funds, and any company where the person isn't an SEC-reporting insider. For informational purposes only.

Loading insider history…
Disclosed Exposure

$49.23M

Companies

5

Total Filings

18

Lifetime Open-Market Net

-$150.37M

Holdings By Company

Latest on-record share count from this person's most recent non-derivative Form 4 transaction in each company. Disclosed exposure = shares × current underlying price.
Symbol Role Shares Price Disclosed Exposure Lifetime OM Net Filings Latest Filed
Solaris Energy Infrastructure, Inc. (SOI) Delisted 10%+ Owner 975,000 $11.32 $11.04M -$135.66M 6 2024-12-18
REPX 10%+ Owner 390,860 $32.98 $12.89M $0 2 2023-07-18
Brigham Minerals, Inc. (MNRL) Delisted 10%+ Owner 2,683,371 $32.50 $87.21M -$13.94M 1 2019-12-18
METC 10%+ Owner 3,726,959 $9.75 $36.34M -$766.9K 1 2017-02-10
Extraction Oil & Gas, Inc. (XOG) Delisted 10%+ Owner 17,554,262 $68.54 $1.20B $0 1 2016-10-31

Recent Filings

18 filings
Insider activity across all companies, newest first. Form 4 rows are post-trade confirmations (buys, sells, grants, exercises). Notice (144) rows are pre-trade notices of intent to sell restricted or control stock under Rule 144 — they may not all execute. Compare adjacent dates to see which notices became actual sales.
Filed Symbol Action Net Shares Net $ Link
2026-05-08 SEI Notice (144) −2,000,000 -$149.00M EDGAR
2026-03-24 METC Notice (144) −49,928 -$573.7K EDGAR
2026-03-05 METC Notice (144) −533,284 -$8.45M EDGAR
2025-03-20 METC Notice (144) −266,642 -$2.48M EDGAR
2025-03-20 METC Notice (144) −49,604 -$425.1K EDGAR
2024-12-18 Solaris Energy Infrastructure, Inc. (SOI) Delisted Mixed −975,000 -$23.41M EDGAR
2023-11-13 METC Notice (144) −25,383 -$412.5K EDGAR
2023-11-13 METC Notice (144) −496,682 -$9.09M EDGAR
2023-07-18 REPX Other (J) −5,376,270 $0 EDGAR
2021-07-30 REPX Mixed $0 EDGAR
Showing 110 of 18
Page 1 of 2
Form 4 codes: P = open-market purchase · S = open-market sale · A = grant/award · M = option exercise · F = tax withholding at vest · G = bona-fide gift · D = disposition to issuer · J = other (see filing footnote). Only P / S codes carry directional signal.
Notice (144 / 144/A): Form 144 is a notice of intent to sell restricted/control stock under Rule 144, filed before the sale; 144/A is an amendment. Many notices are pre-scheduled under Rule 10b5-1 plans. A Form 4 with code S typically follows within a few days when the planned sale executes; missing follow-up Form 4s suggest the notice was cancelled or modified.