Still got it, but the problem is I know what I want to do, but not how to do it.
So theoretically I want to add a short to preferably at a new position; so
Do I sell market/limit/stop/trailing stop
or do I buy market/limit/stop/trailing stop
Or the better option; open a new account and short from scratch.... which seems to defeat the purpose really.
Yeah opening a new account just to short is a bad idea - as your short makes money your long simultaneously loses roughly the same amount. Better off reducing your commitment. Selling half a stock you hold and buying it at a lower price has the same effect
as having no stock and short selling the same amount and buying it back later...just different terms for slightly different things. It's all about making a prediction on the price and getting it right.
A short can be thought of as "selling stock", only you don't have the stock to sell. It's still related to selling, though, so if you have 100 btc and sell it for $5, buying back at $4, it's the same as borrowing 100 btc and selling it at $5, and buying it back at $4. That means in bitcoinica, which has a pseudo short sell, selling in that combines the two.
With that in mind, if you want to sell the stock you have at a certain price, put a limit (eg $5.50 limit for 200 sold). If you then want to then make a short sell at that same price, do another limit for how many short at the same price (eg another $5.50 for 200 sold). If you had 200 btc to begin with, if the price hits $5.50 you'll effectively sell those and short sell an extra 200 btc.
Market just means do it right now...only use this when you really want to just get out or get in as quickly as possible. Liquidate is just a market order with how many btc you have/don't have, and is no faster than a market order.
Stop means "activate this as a market order once this limit is hit" - guarantees a buy/sell once a trigger has been hit whereas a limit does not...useful if you don't want to watch it all the time.
Trailing stop...haven't used them before so I don't know that one. I think it's supposed to always change and set itself to some percentage less than what target you put in, so if it loses profitability it automatically closes the position.
Does that help?