The company reported it had repurchased 6.3 million of the authorised 18.3 million, or 10%, of outstanding shares under the normal course issuer bid, including 800,000 in April alone.
Sandstorm said the actual number of common shares that might be bought and the timing of such transactions would be determined by the company.
"Decisions regarding purchases will be based on market conditions, share price, best use of available cash, and other factors," it said.
Sandstorm also reported it had received its first silver delivery under the Cerro Moro stream agreement with owner Yamana Gold. The delivery of 300,000 ounces represented the maximum quarterly amount under the stream agreement.
Argentina-based Cerro Moro, where Yamana recently announced a 33% exploration budget increase for 2019, is expected to produce 6 million ounces of silver in 2019.
Sandstorm has gained 22% over the past 12 months, with Wednesday's gains of 1.73% or C12c (US8.9c) in Toronto pushing the year-to-date gains up 14% to $7.06. This capitalises the company at $1.3 billion.