Frank Addante Net Worth 2026: Estimate, Assets & Timeline

Frank Addante's net worth, based strictly on his documented public equity in Magnite (NASDAQ: MGNI) and dated to the market close of July 27, 2026, falls in an estimated range of approximately $21.7 million to $58.4 million USD. That range reflects genuine uncertainty about how many shares he currently holds, because the most recent Form 4 filings publicly available date back to 2020. The honest answer is that no single figure can be pinned down without private documents, and anyone quoting a tidy round number without sourcing deserves skepticism. For a related discussion, see the companion piece on Frank Adonis net worth for additional context and comparison.

Net Worth Snapshot

Net Worth Estimate: Range, Date, Currency, and Confidence

The defensible public-evidence range for Frank Addante's net worth is $21.7 million to $58.4 million USD, stamped to the MGNI market close of $19.09 on July 27, 2026. That spread is wide by design. It reflects three distinct scenarios derived from real SEC filings, not guesswork.

The low end is likely the most realistic reflection of his current public equity, because a series of Rule 10b5-1 and open-market sell transactions documented in Form 4 filings between 2017 and 2020 progressively reduced his reported position. The high-end figure would only apply if he made zero net sales after the 2014 IPO, which the subsequent Form 4 record disproves. I am treating the $21.7M figure as the floor of the public-equity component, with the actual current holding likely sitting somewhere in the lower portion of the range.

Critically, this range captures only his documented Magnite equity. It does not include cash proceeds from prior share sales, private company investments, real estate, or any other personal assets. Confidence is rated low-to-moderate: moderate because the share counts are anchored to actual SEC filings; low because the most recent filing data is now more than five years old and material changes could have occurred since.

How Frank Addante Built His Wealth: Career and Income Streams

Frank Addante is a serial entrepreneur whose wealth stems almost entirely from founding and scaling technology companies in the digital advertising and internet infrastructure space. Unlike executives who built wealth through salary accumulation, Addante's financial story is a founder's story: equity stakes in startups that either exited, went public, or grew into significant businesses.

Early Ventures: Starting Point and L90

Addante's first notable company was Starting Point, an early internet search engine he founded before the Google era made search a winner-take-all market. He then moved into online advertising as co-founder and CTO of L90, which operated the adMonitor platform. L90 was an early player in the ad-serving space during the late 1990s and early 2000s dot-com boom. These companies were formative for his technical skill set and his network in digital advertising, but they are not documented sources of large documented exits in public records.

StrongMail Systems: Email Infrastructure (2002)

In 2002, Addante founded StrongMail Systems, an email infrastructure company targeting enterprise-level email delivery and marketing. StrongMail operated in a niche that was genuinely valuable before cloud email delivery platforms became commoditized. The company raised venture capital and built a customer base, but it was never publicly listed. Public records do not show a large disclosed exit for Addante personally, and residual private equity from StrongMail, if any, remains unverified in public sources.

The Rubicon Project and Magnite: The Main Wealth Event

The Rubicon Project, which Addante founded in 2007, is the central wealth-building event of his career. The company built programmatic advertising infrastructure, helping publishers automate the sale of their digital ad inventory. It went public on the NASDAQ in April 2014 under the ticker RUBI. That IPO is where Addante's equity converted into a publicly trackable, documented financial asset. At the time of the S-1 registration, he held 3,059,374 shares.

The Rubicon Project later merged with Telaria in 2020 to form Magnite, Inc. (NASDAQ: MGNI), now one of the largest independent sell-side advertising platforms. Addante's executive role at the company continued through and beyond the merger, making Magnite the single most important and documentable component of his estimated net worth.

Executive Compensation and Other Income Streams

As a named executive officer at a public company, Addante received annual compensation packages that included base salary, cash bonuses, and equity awards (restricted stock units and options). These are disclosed in annual proxy statements and 10-K filings. While specific figures from individual years are not consolidated here, executive compensation at a company of Rubicon/Magnite's size typically ranged from several hundred thousand to low millions annually for a founder-CEO. Equity grants would have added to his baseline share count over time, partially offsetting shares sold.

Other potential income streams include advisory roles, board positions at portfolio or peer companies, and speaking or consulting fees. These are not publicly documented at amounts that would materially change a net-worth estimate, but they represent ongoing cash flow that likely supports his personal balance sheet independent of stock sales.

Likely Assets and Liabilities

What follows is an itemized breakdown of probable assets and liabilities based on public records and reasonable inference. Items marked as estimated or likely are not verified by primary documents and should be treated as informed assumptions pending direct research.

• Magnite (MGNI) equity: Documented in SEC filings; estimated current value $21.7M–$30.9M based on most recent Form 4 data (2020 and 2017 snapshots respectively), using $19.09 close price dated July 27, 2026.
• Cash and liquid investments: Likely material, given a series of documented share sales between 2017 and 2020 that generated realized proceeds; exact amount unverified in public records.
• Vested stock options or RSUs at Magnite: Possible but not quantified; would require current equity award schedule from company records or recent Form 4 disclosures.
• Residual equity in StrongMail Systems or successor entity: Possible but unverified; no public documentation of a large exit or current valuation found.
• Private investments and angel/VC portfolio: Likely given his profile as a serial founder with industry connections; not documented in public records available.
• Real estate: Not verified through county assessor or recorder searches; one or more residential properties in the Los Angeles area are plausible given his career base, but this is inferred, not confirmed.
• Personal property (vehicles, art, other valuables): No public documentation; omitted from range calculation.
• Mortgage debt: Possible on any real estate holdings; amount unverified.
• Income tax liabilities on share sales: Share sales between 2017 and 2020 would have generated capital gains tax obligations; these reduce the net cash value of sale proceeds but are not publicly quantified.
• Other liabilities (judgments, liens, UCC filings): No evidence found in public sources; PACER and state court searches have not been completed for this profile and would be required for a full publication-grade estimate.

Financial Timeline: Major Deals, Exits, and Share Transactions

The timeline below traces the documented financial milestones in Frank Addante's career, drawn from SEC filings and public company disclosures. This is the backbone of any credible net-worth estimate for a founder whose wealth is equity-driven.

Estimation Notes, Key Assumptions, and Source Citations

Transparency about methodology is non-negotiable for a profile like this. Here is exactly how the numbers in this article were produced, what was assumed, and what remains unknown.

Step 1: Assemble Primary Documents

All share-count figures used in this profile originate from SEC EDGAR primary filings: the Rubicon Project S-1 prospectus (2014) for the IPO-era ownership figure; the DEF 14A proxy statement (2015) for the first post-IPO snapshot; a Form 4 filed in 2018 covering a transaction dated November 15, 2017, for the mid-period position; and aggregated Form 4 data compiled by Fintel and Capitalizator reflecting transactions through March 2020 for the most recent documented position. The 2026 Magnite DEF 14A was reviewed as negative evidence: Addante does not appear in the current ownership table for major beneficial holders. The 2026 Magnite DEF 14A was reviewed as negative evidence: Addante does not appear in the current ownership table for major beneficial holders blank" rel="noopener noreferrer">The 2026 Magnite DEF 14A was reviewed as negative evidence: Addante does not appear in the current ownership table for major beneficial holders..

Step 2: Value Public Equity

Public equity valuation follows the straightforward formula: shares held multiplied by the closing market price on a specific date. The price used throughout this profile is $19.09, the verified MGNI closing price on July 27, 2026, sourced from Investing. Investing.com historical data shows MGNI closed at $19.09 on July 27, 2026 Investing.com historical data shows MGNI closed at $19.09 on July 27, 2026.. com historical data. Three scenarios are presented to reflect the genuine uncertainty in current share count, spanning the range from the most recent documented position (1,134,819 shares) to the original IPO-era position (3,059,374 shares).

Step 3: Acknowledge Private Assets and Liabilities

The public-equity estimate is a floor calculation, not a full net-worth figure. A publication-grade profile would additionally require: current brokerage statements for cash and investment accounts; transfer or escrow documents from any secondary market share sales; private cap-table records for StrongMail or other private companies; county assessor and recorder records for real estate (Los Angeles County and any other relevant jurisdictions); UCC filings for secured debt; and PACER searches for federal court judgments or liens. None of these have been completed for this profile, and their omission is explicitly stated.

Key Assumptions Listed

• The MGNI share price of $19.09 (July 27, 2026 close) is treated as the current market reference; a different date would produce a different result.
• The most recent Form 4 aggregate (approximately 1,134,819 shares, March 2020) is assumed to be the most accurate publicly available figure for current holdings, with the caveat that it may be outdated by more than five years.
• No additional equity grants or purchases are assumed post-2020 in the absence of documented Form 4 filings, though equity awards from the company are plausible and could increase the actual position.
• No large private exits (StrongMail, other investments) are factored in due to absence of documented deal terms or valuations in public records.
• Tax liabilities on realized stock sales are acknowledged but not quantified; they reduce net cash value of prior sales.
• Real estate and other personal assets are excluded due to absence of verified public records.

Source Reference List

1. Magnite, Inc. executive biography page — Frank Addante identity and founding company history.
2. The Rubicon Project S-1 Prospectus, SEC EDGAR (2014) — IPO-era share ownership: 3,059,374 shares.
3. The Rubicon Project DEF 14A Proxy Statement, SEC EDGAR (2015) — Post-IPO beneficial ownership: 2,879,488 shares.
4. SEC EDGAR Form 4, filed 2018, period of report 2017-11-15 (ADDANTE FRANK / Rubicon Project) — Post-transaction holdings: 1,620,245 shares.
5. Fintel / Capitalizator — Compiled Form 4 transaction history for ADDANTE FRANK (MGNI); aggregate position as of March 2020: approximately 1,134,819 shares.
6. Magnite, Inc. DEF 14A Proxy Statement (filed April 2026, meeting June 8, 2026) — Current ownership table reviewed; Addante not listed as major beneficial owner.
7. Investing.com — Magnite (MGNI) historical closing price, July 27, 2026: $19.09.
8. SEC.gov — Guidance on ownership reports and trading by officers, directors, and principal security holders (Forms 3, 4, and 5).
9. Corporate Finance Institute — Startup and private-company valuation methodology reference.

Reader Questions: Accuracy, Why Ranges Differ, and How Often This Gets Updated

How accurate is this estimate?

The public-equity component is as accurate as the SEC filing record allows. The share counts are taken directly from primary documents, and the stock price is a verified market close. The uncertainty comes from the gap between the most recent public filing (2020) and today: if Addante has sold shares, received new grants, or held the position flat, the actual number could be higher or lower than the $21.7M floor used here. The full personal net worth, which would include cash from prior sales, real estate, and private investments, is genuinely unknown without private documents.

Why do different sources quote different numbers?

Most net-worth figures published on general celebrity or finance websites are not sourced to specific SEC filings or dated stock prices. For a comparable founder-profile approach, see the Frank Azevedo net worth page for how similar public-equity and filing-based estimates are presented. They often use outdated share counts, ignore taxes on sales, or simply round a prior estimate and republish it. This profile uses a documented range precisely because a single number would be misleading. The spread from $21.7M to $58.4M reflects real filing-based scenarios, not editorial convenience.

How often does this profile get updated?

This profile targets a review whenever a new Form 4 filing appears on SEC EDGAR for Frank Addante, whenever Magnite files an annual proxy (DEF 14A) that updates executive ownership tables, or when the MGNI stock price moves materially enough to shift the estimated range by more than $5 million. Readers who want a real-time view of the public equity component should check MGNI's current price and multiply by the most recently documented share count from SEC EDGAR directly.

Putting Addante's Wealth in Context

An estimated range of $21.7M to $58.4M in documented public equity puts Frank Addante in the tier of successful technology founders who built real companies and exited via the public markets, but did not achieve the nine-figure or ten-figure outcomes associated with household-name tech founders. That is an important distinction. Addante spent more than two decades building infrastructure companies in digital advertising, a space that attracted far less investor enthusiasm and public attention than consumer tech. The Rubicon Project was a genuine market leader in programmatic advertising, and Magnite continues to operate as a significant independent platform.

The documented sell-down of his shares between 2014 and 2020 is consistent with standard founder behavior after an IPO lock-up period expires: diversifying out of a concentrated position is rational, and the proceeds from those sales likely represent a meaningful portion of his actual liquid net worth. Without knowing the exact prices at which those sales occurred, it is impossible to calculate the total realized cash value, but even modest prices in the $5–$15 range that RUBI traded during much of 2015–2019 would put total realized proceeds in the range of tens of millions of dollars.

Readers interested in comparing founder wealth trajectories across this site may find it useful to look at profiles such as Frank D'Amelio, whose wealth came from a very different executive compensation model in the pharmaceutical sector, or Frank Amodeo, whose story includes significant legal and financial reversals. The contrast illustrates how differently the math works depending on whether wealth is built through equity founding, salary, or other means.

Corrections and Updates

If you have access to more recent Form 4 filings, verified county property records, or other primary documents that would update or correct any figure in this profile, please use the contact form on this site. For related coverage, see the frank azor net worth profile. For related coverage, see frank amodeo net worth for a comparable founder net-worth profile. We treat corrections as improvements, not corrections, and the methodology section above reflects every assumption that could be revised with better data. This profile was last reviewed on August 8, 2026, using the most recent publicly available SEC filings and the MGNI market close of July 27, 2026. For related methodology and context, see the profile on Frank Amedia net worth.