TheMotorcycleBoy wrote:So is an 'at best' order basically the same as a 'market order?'
No and yes and no! It depends on the context...
In the context of this thread, i.e. LSE auctions, no - a 'market order' is a special type of order that is only active in the LSE order book system during auctions, as I described above in post #216339 (at the end of my first section).
In the more informal, less technical context of the Investopedia definition you found, yes - I'd guess its origin is the idea that the investor finds it OK to go along with the best price the market is placing on the share.
In a still less formal context, no, the phrase could mean any order of any type placed with the market.
Gengulphus