WINMILL MARK CAMPBELL purchased ~$64K in Global Self Storage, Inc. stock
Global Self Storage, Inc. (SELF) · Data via SEC EDGAR Form 4
Price Performance · 10 days before → 90 days after trade
▲ = insider buy date
Trade Details · Public SEC Filing
Insider
WINMILL MARK CAMPBELL
Role
—
Transaction
Open-Market Purchase
Approx. Value
~$64K
Trade Date
May 14, 2026
Company
Global Self Storage, Inc.
Ticker
SELFSource
SEC EDGAR Form 4
Why This Trade Stands Out
Very Strong conviction signal
Scored in the top tier across multiple factors. Fewer than 5% of insider trades receive this rating.
~$64K purchase
A personal investment by a corporate insider. Even smaller trades can be meaningful when combined with other factors like timing and role.
How good is WINMILL MARK CAMPBELL at picking stocks?
Full track record: win rate, average return, and performance vs S&P 500
On May 14, 2026, WINMILL MARK CAMPBELL — a corporate insider at Global Self Storage, Inc. — filed a Form 4 with the SEC disclosing an open-market purchase of approximately ~$64K in Global Self Storage, Inc. (SELF) stock.
Under Section 16(a) of the Securities Exchange Act of 1934, corporate insiders must report all open-market stock transactions to the SEC within two business days. These filings — known as Form 4s — are publicly available on the SEC's EDGAR database. VeritySignals filters and scores the full Form 4 stream to surface high-conviction signals like this one.
VeritySignals Conviction Analysis
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All data sourced from publicly available SEC Form 4 filings via EDGAR · Not financial advice · Past performance does not guarantee future results.
At a Glance
More SELF Insider Activity
WINMILL MARK CAMPBELL
May 14, 2026
~$64K
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How to Read Insider Trades
What is this?
When company executives buy or sell their own stock, they must report it to the SEC within 2 days. These public filings reveal what the people who know the company best are doing with their own money.
Why does it matter?
Insiders can sell for many reasons (taxes, diversification, expenses), but they generally only buy for one: they think the stock is going up. That's why insider purchases are more predictive than sales.
What makes a trade "strong"?
We score trades on 15+ factors: the insider's role (CEO > director), trade size relative to their salary, whether other insiders also bought (clusters), and historical accuracy of the insider.
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