Just sharing some interesting features when placing orders.
1) Display size
Hidden means your order will be sent to the exchange but hidden from others.
Why use this? It's meant to cut queue when placing BID/ASK order without people knowing.
For example, let's say the BID/ASK is $2.50/$3.00 and you want to buy this stock.
If you queue at $2.51 BID, people might cut your queue by placing $2.52.
You must then change to $2.53. The other person might change to $2.54.
However, if you place a hidden order at $2.51 when the BID/ASK is $2.50/$3.00.
If someone sells at market order, your order will be executed at $2.51 before $2.50.
Disadvantages? Stocks are matched by prioritising PRICE > DISPLAY > TIME.
Meaning if you put a hidden order at $2.50 instead when people queue without hidden, the non-hidden orders will get executed first even though you placed the hidden order earlier.
2) Market on close
Usually we don't use this and it's institutional investors who manage funds who use this.
Mainly applied to BUY orders.
You may ask but why use market on close when you can likely get a better price if you buy before market close?
Reason is they do not want to reflect any gain/loss on the transaction.
Meaning if their accounting books close at 31st Dec and they want to buy a stock that fluctuates between $9~$10, buying at close means there will be no gain no loss.