T2W Trading Community

9. Money Management Rules

Once we have developed the actual trading rules there is one further, important, consideration – how much to risk on each trade. Good money management serves two purposes:

• Minimises the risk of losing the whole trading account before the system edge has a chance to work out.
  
• Maximises the potential of the trading system when conditions are favourable.

Many traders will, mistakenly, try to minimise their risk by setting tighter stop levels. Stop levels should, actually, be set as a function of market action. If the losses taken when those stops are hit are unacceptable to us then we should reduce the number of contracts traded, rather than merely tighten the stop. As we have seen this course of action is likely to lead to increased losing trades and an overall degradation of the system performance. In other words, money management controls risk not stop orders.

In order to establish money management rules for our system we need to examine how it has performed over our test period:

Test Period:	January – June 2004
Total Points Profit:	1012
Total Trades:	80
Allowance for Slippage/Commission (3pts per trade):	(240)
Net Profit:	772
Maximum Draw down:	181

For money management we are most interested in the maximum drawdown. The mini-Dow trades at $5 per point so the maximum draw down on 1 contract was 181 x $5 or $905. In order to trade through this period with one contract we would have needed a minimum of $905 plus the minimum account balance requirement (for Interactive Brokers) of $2,000 = $2,905.

However, future performance of the system is unlikely to replicate our test period so for this reason we must be rather more conservative. Remember our objectives with money management – minimise the chances of losing everything whilst maximising the potential.

If we double our historical maximum drawdown of $905 and add on the minimum account balance requirement of $2,000 we get $3,810. So, if we begin trading 1 contract with $4,000 in our account we would need to immediately start a losing sequence which is twice as big as the maximum during our testing period in order to not be able to continue trading the system. A situation which could, of course, happen but is reasonably unlikely.

The risk per trade may seem very high, if our stop is 50 points or $250 then we are risking 6.25% of our account where many books will recommend just 1%. However, remember our objective with money management is to maximise the potential of our system. The only way to do that with a small account size is to increase risk to the limit of acceptability - we have shown that even at this higher level of risk we are unlikely to lose the whole account. If we were to risk only 1% then we would need at least $25,000 to trade just 1 contract, which given our maximum historic draw down of only $905 is blatantly over the top.

Once we have established the minimum required to begin trading the system we should look at how we will increase the number of contracts traded as the account balance grows. There are 2 main variations:

Fixed Fractional. Here we will trade 1 contract for every $x in the account. In our example that is 1 contract for every $4,000. So at $8,000 we will trade 2 contracts, at $12,000 3 contracts and so on. Note, that if the account balance drops back below the threshold we will drop a contract. In summary:

Account balance required:	Contracts:
4,000	1
8,000	2
12,000	3
16,000	4
20,000	5
24,000	6
28,000	7
32,000	8
36,000	9
40,000	10

We can continue to trade 1 contract below $4,000 down to the account minimum of $2,000 as established earlier.

Fixed Fractional is a popular method of money management however it has a serious flaw. That is, it requires unequal achievement at different contract levels. To move from 1 contract to 2 we are required to make a profit of $4,000 from trading 1 contract. However, to move from 2 contracts to 3 contracts we still require $4,000 of profit but this time from 2 contracts. This means that small account balances will take time to grow and for larger account balances the number of contracts traded will jump wildly around. It is not suited to either small or large accounts!

Fixed Ratio: Resolves the problem of fixed fractional by adding a variable to the calculation. This variable (or delta) is the amount required per contract to move to the next level. The lower the delta the more aggressive the system will be.

The formula is:

equity required to trade previous contract size + (number of contracts x delta) = Next level.

If we use $4,000 as our base level for 1 contract and a delta of $1,000 we get:

Account balance required:	Contracts:
4,000	1
5,000	2
7,000	3
10,000	4
14,000	5
19,000	6
25,000	7
32,000	8
40,000	9
49,000	10

Comparing the tables shows that at lower account balances the risk is higher (we can trade more contracts) but as the account grows the risk is reduced. For example with an account balance of $10,000 we would be trading 4 contracts against only 2 for fixed fractional. For an account balance of $40,000, though, we will only trade 9 contracts against 10 for fixed fractional. If the account falls below $4,000 we will continue to trade just 1 contract with both methods.

Fixed fractional allows us to be aggressive with a small account and reduce the risk as the account balance grows.