SCHEDULE 13G/A

NCS MULTISTAGE HOLDINGS, INC.

Common Stock, par value $0.01 per share · CUSIP: 628877102

Event date: 2025-03-31

Reporting persons may disclose overlapping interests. Their amounts are shown individually and are not added into a filing total.

Filing-level shares

Unavailable

Percent of class

Unavailable

• ADVENT INTERNATIONAL, L.P.

  Shares: 1,478,426 · Class: 58.19%

• Advent International GPE VII LLC

  Shares: 1,478,426 · Class: 58.19%

• Advent-NCS Acquisition Limited Partnership

  Shares: 1,478,426 · Class: 58.19%

• Advent-NCS GP LLC

  Shares: 1,478,426 · Class: 58.19%

• GPE VII GP Limited Partnership

  Shares: 504,439 · Class: 19.85%

• GPE VII GP (Delaware) Limited Partnership

  Shares: 941,019 · Class: 37.04%

• Advent Partners GPE VII Limited Partnership

  Shares: 591 · Class: 0.02%

• Advent Partners GPE VII-A Limited Partnership

  Shares: 1,478 · Class: 0.06%

• Advent Partners GPE VII-B Cayman Limited Partnership

  Shares: 14,489 · Class: 0.57%

• Advent Partners GPE VII Cayman Limited Partnership

  Shares: 13,010 · Class: 0.51%

• Advent Partners GPE VII-A Cayman Limited Partnership

  Shares: 3,400 · Class: 0.13%

• Advent International GPE VII Limited Partnership

  Shares: 184,655 · Class: 7.27%

• Advent International GPE VII-A Limited Partnership

  Shares: 170,906 · Class: 6.73%

• Advent International GPE VII-B Limited Partnership

  Shares: 429,483 · Class: 16.9%

• Advent International GPE VII-C Limited Partnership

  Shares: 136,459 · Class: 5.37%

• Advent International GPE VII-D Limited Partnership

  Shares: 110,586 · Class: 4.35%

• Advent International GPE VII-E Limited Partnership

  Shares: 309,435 · Class: 12.18%

• Advent International GPE VII-F Limited Partnership

  Shares: 39,918 · Class: 1.57%

• Advent International GPE VII-G Limited Partnership

  Shares: 39,918 · Class: 1.57%

• Advent International GPE VII-H Limited Partnership

  Shares: 24,098 · Class: 0.95%

Amounts are as disclosed in this filing. Schedule type alone does not establish investment intent.