First I would like to say thanks to Goomboo and the others who have been contributing to this thread. I read through the entire thing, and have learned a great deal. I'm in the process of backtesting now to decide on my strategy, but I have a few questions about risk management and leverage.
Early in the thread, Goomboo wrote the following:
I do use Bitcoinica, but I DO NOT use more than 2.5 times leverage. My method is a trend following system which simply means I'm looking for a new trend to start and I want to be trading in the direction of that trend as long as it remains. Trend following systems typically only have a 30% profitability ratio which means that if you trade, you have a 70% chance of being wrong and losing money on that trade. If you are using 10:1 leverage and are wrong 3-5 times in a row, you're bankrupt!
I have no finance background so I'm having some trouble following this. If my understanding of leverage is correct, it would mean borrowing USD to buy BTC for long positions, and/or borrowing BTC to buy USD for short positions. If this is correct, then I have some specific questions:
1. Regarding '2.5 times leverage', does this mean for example that you're putting up 2.5 $ for every 1 $ you borrow when buying BTC? Or that you borrow 2.5$ for every 1 $ of your own?
2. How would this work for going short? I would think in that case you would sell your full BTC position (which itself may be leveraged) and then possibly borrow and sell additional BTC. What does the 2.5x refer to in this case?
3. Is 'shorting' BTC still viable post-Bitcoinica? Do any high-volume exchanges offer it now? I saw earlier in the thread that Goomboo was just selling his position on down-crosses and buying back in on up-crosses. Is shorting on a downturn any riskier than buying in on an upturn, or just another layer of complexity?
Leverage is great in some situations, but it is a double-edged sword. The beautiful thing about leverage from my perspective is that it allows individuals to practice fixed-fractional money management on lower timeframes. Basically this means that leverage allows you to adhere to your risk management system by giving you buying power.
An example of an appropriate use of leverage:
-You have a $1,000 account.
-You are willing to risk 2% on a trade. This means that if you're wrong, you lose $20.
-You know that a logical stop / place for you to exit if you are wrong is $.30 away from the market price.
-This means that you should buy > Dollars At Risk / Price move > $20 / $.30 = 66 bitcoin. If you didn't have the money to buy 66 bitcoin, leverage finds a use.
I think I'm understanding most of this, but I'm struggling to see how leverage comes into play here. Here is my interpretation of the above example:
1. $1,000 account refers to how much of my own money I want to 'play with' in BTC (maximum I want to risk).
2. Rather than buying 1000$ worth of BTC (risking it all on one trade), I want to limit my potential losses to 2% of my account balance per trade to make sure that I can handle a string of losses without losing much.
3. By using a percentage of account balance as my exit point, my losses per trade will shrink if I continue to lose money (first 20$, then 19.60$, then 19.20$...).
4. Risking 20$ per trade doesn't mean buying 20$ worth of BTC, because I'm planning an exit point in advance (to lose 20$ on a 20$ trade would mean holding BTC all the way down to zero).
5. At the time of this example, the price was about 6$ per BTC; and a price move of $0.30 against my position would have been a reasonable exit point, meaning I would only lose $0.30 per BTC. To make this amount to 20$ in total would mean buying ($20 total)/($0.30 per BTC) = 66 BTC, or about 400$ worth of BTC.
6. *If you didn't have the money to buy 66 bitcoin, leverage finds a use.* Here's where I'm running into trouble. If I didn't have 400$ to buy 66 BTC, then the above calculation would never have told me to buy that many. For example, if I only had 300$, then 300*0.02=6$ would have been my maximum loss per trade. In this case I should only be buying 6$/0.30=20BTC or 120$ worth (which I can afford without leverage).
The only way I can see to include leverage in this example is if the max loss per trade is kept at 20$ regardless of the account balance, but wouldn't this mean increasing rather than decreasing risk as losses accrue? Additionally, I'm having trouble seeing how the selection of a particular exit point is compatible with the moving average crossover strategies. Isn't the exit point determined by the next crossover, and thus not known in advance? Or is the crossover strategy meant to include these predetermined exit points to protect against rapid price changes and provide a way to quantify and limit maximum loss?