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AmpliTech Group

AMPG on Nasdaq. Market value $89m.

Watch this stockFree. We tell you when something changes.

Should I look at this?

Look carefully before going further

Why it could be worth it

Nothing stands out yet.

What to watch out for

Read the warning sign in its own filings

This is not advice.

Compare with another stock

Who owns it

None of the long-term investors we follow own it. 64 funds in all.

Jun '25
Dec '25
Jun '26
Largest holders overall

From 13F filings for the quarter ended 30 June 2026.

Big holders and activists

3 investors own more than 5%.

  • Bard Associates, Inc.
    Passive investor
    8.8%
    Since 7 January 2025
  • G1 Execution Services, LLC
    Passive investor
    at least 6.9%
    (filed with 2 related holders)
    Since 30 June 2026
  • Citadel Securities GP LLC
    Passive investor
    at least 5.7%
    (filed with 6 related holders)
    Since 30 June 2026
  • The Vanguard Group
    Passive investor
    Sold down below 5%
    Since 13 March 2026

From Schedule 13D and 13G filings: anyone owning more than 5% must file one.

What insiders did

In the last 12 months, 2 insiders bought $48,449 of shares on the open market. 3 sold $587,948.

  • Maqbool Fawad
    Chief Executive Officer, Director
    Bought
    Date
    20 August 2026
    Shares
    12,247
    Price
    $3.48
    Value
    $42,649
  • Mazziota Daniel Richard
    Director
    Sold
    Date
    23 June 2026
    Shares
    10,000
    Price
    $7.71
    Value
    $77,100
  • Mazziota Daniel Richard
    Director
    Sold
    Date
    22 June 2026
    Shares
    7,157
    Price
    $8.46
    Value
    $60,548
  • Flores Jorge Luis
    Chief Operating Officer
    Sold
    Date
    1 June 2026
    Shares
    30,000
    Price
    $5.36
    Value
    $160,800
  • Sanfratello Louisa
    Chief Financial Officer, Director
    Sold
    Date
    28 May 2026
    Shares
    50,000
    Price
    $4.80
    Value
    $240,000
  • Mazziota Daniel Richard
    Director
    Sold
    Date
    22 May 2026
    Shares
    10,000
    Price
    $4.95
    Value
    $49,500
  • Modi Shailesh
    Director
    Bought
    Date
    18 December 2025
    Shares
    2,000
    Price
    $2.90
    Value
    $5,800

From Form 4 filings: insiders must report trades in their own company's shares within two days.

Warning signs in its filings

Problems the company itself reported to the SEC, in its own words.

1 serious warning sign in AmpliTech Group’s filings.

We look for five warning signs: doubt it can keep going, weak checks on its own accounts, a notice that its past accounts can't be relied on, a change of auditor, and one customer bringing in a big share of sales. We don't check lawsuits, investigations or debt yet.

We checked the auditor's report, internal controls, restatement notices, auditor changes and big customers in the 10-K filed 26 Mar 2026, plus the 10-Q filed 13 Aug 2026 and 7 later 8-Ks.

  • Weak checks on its own accounts

    Serious

    The company said its checks on its own accounts did not work at the end of its latest quarter. Mistakes could slip into the numbers.

    “As a result of this evaluation, our chief executive officer and chief financial officer have concluded that, as of June 30, 2026, our disclosure controls and procedures were not effective due to the material weaknesses in internal control over financial reporting described below.”
    Show the full paragraph
    Under the supervision and with the participation of management, including our chief executive officer and chief financial officer, we conducted an evaluation of the effectiveness of our disclosure controls and procedures as of June 30, 2026, as such term is defined in Rules 13a-15(e) and 15d-15(e) of the Exchange Act. As a result of this evaluation, our chief executive officer and chief financial officer have concluded that, as of June 30, 2026, our disclosure controls and procedures were not effective due to the material weaknesses in internal control over financial reporting described below. Notwithstanding the identified material weaknesses, management, including our chief executive officer and chief financial officer, believes the condensed consolidated financial statements included in this report fairly represent, in all material respects, our financial condition, results of operations and cash flows as of and for the periods presented in accordance with GAAP.

    From the 10-Q filed 13 August 2026, Part I, Item 4. Controls and Procedures. Read it in the filing

  • One big customer

    Worth knowing

    One customer brings in a big share of sales: 42.9% last year. Losing that customer would hurt.

    “As of December 31, 2025, there was one customer that accounted for 42.86% of our total revenue.”

    From the 10-K filed 26 March 2026, Item 1. Business. Read it in the filing

A 10-K is the yearly report every US company files with the SEC. An 8-K is a short notice of a big event.

The deep dive

Everything above is arithmetic on public filings. The deep dive reads the last ten years of annual reports, the proxy statements, and the earnings calls, then argues the case the way Buffett, Klarman, and Hohn would, and checks every claim against the source.

  • What the business is worth, as a range, and the margin of safety at today’s price
  • Prices to start buying, buy, and buy hard
  • The three things that would make this a mistake
  • Every number footnoted to the filing it came from
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What a finished deep dive looks like

Not advice. Numbers on this page come from SEC filings and are updated each night; prices are updated again after the US market closes. The five-year figures are rounded.