Sandstorm Gold agreed to sell itself to Royal Gold in a stock deal worth $3.5 billion. The two companies on Monday entered into a definitive arrangement agreement whereby Sandstorm shareholders will receive 0.0625 of a share of Royal Gold stock for each of theirs.

The Sandstorm deal is a share swap that values Sandstorm at about $3.5 billion, the companies said. Meanwhile, Royal Gold will buy Horizon for C$2 a share in a C$267.5 million (S196 million) all-cash acquisition. Royal Gold stock was slumping 8.5% to $164.62 following the announcement.