New auction
Five steps to a signed create_auction extrinsic. Deposits are always 5% of a bid, collected from bidders when they bid.
English Auction
Ascending price. Bidders openly compete; each bid must beat the current price by the minimum increment. Highest bid at close wins.
Dutch Auction
Descending price. The price drops every block; the first bidder to accept the current price wins instantly.
Sealed-Bid Tender
Commit-reveal. Bidders submit a hashed commitment while open, then reveal amount and salt during the reveal phase. Used for government tenders.
Fixed Allocation Sale
Fixed price offering. Multiple bidders purchase allocations at the starting price; minimum bid equals the starting price.