On the open market
Definition 1 of 2
Pro Tip 1/3Wider Availability
Indicates an item can be bought by anyone, not restricted to private deals or auctions. 
After years of exclusivity, the vintage wine collection was finally available on the open market.
Pro Tip 2/3No Insider Needed
You don't need special access or connections to purchase something on the open market. 
Unlike some rare items, this book is readily found on the open market.
Pro Tip 3/3Impersonal Transactions
On the open market, buyers and sellers often do not know each other. 
The stocks were sold quickly on the open market to anonymous buyers.