From the desk · Risk
The 2015 Sizing Mistake
In 2015, a few hours erased months of gains from my trading. The lesson is about the size of a position and the loss it can create, not about the comfort of a convincing market view. The full scene still needs the details only I can supply.
In 2015 I lost months of trading gains in a few hours. I had experience behind me. I had traded my own capital for years. That did not stop the loss.
The lasting lesson was about position size. A view can make sense and the amount of risk attached to it can still be wrong. A previous run of profitable decisions does not change the consequences of the next position.
The view and the exposure are separate decisions
It is easy to spend most of the research time on direction. What happens to rates? Where does the price go? What confirms the setup? Those questions matter. They are incomplete until the position is translated into exposure and possible loss. An accurate explanation of direction cannot be spent to meet a margin call. Conviction does not reduce the dollars at risk.
That distinction changed how I thought about trading. The question became more demanding than “am I right?” It included “what does this position do to the account if I am wrong, or if the path is worse than I expected?”
From the desk
A trading record cannot protect the next position. What protects it is the risk arrangement made before the move arrives, and an honest allowance for what that arrangement cannot guarantee.
Planned loss is not possible loss
A stop and a position-size calculation describe a planned exit under particular assumptions. The market can gap. Liquidity can thin out. Execution can occur away from the level written on the plan. A leveraged instrument can require cash before the broader thesis has time to play out. These are general mechanisms, not a claim that every one occurred in the 2015 loss. The point is to test the assumptions behind the size, rather than treat one number as a guaranteed maximum.
Hypothetical sizing example
An account holds $100,000. A position of 1,000 shares bought at $10 with a planned $9.50 exit implies a $500 loss before costs. If an unexpected event produces an exit at $8.50, the loss is $1,500. Doubling the position doubles both figures. This is an illustration of gap and sizing risk, not a reconstruction of the 2015 trade.
The whole account has to survive
Several positions can each appear manageable and still express the same underlying view. A portfolio containing different tickers may depend on one interest-rate outcome, sector or source of liquidity. Inspect each position under adverse conditions. Then inspect the account if the positions are adverse together. Diversification cannot be inferred from the number of lines in the statement.
For a household, the consequences include the need for money outside the account. A drawdown funded by spare risk capital and a drawdown that changes essential spending are different events even if the percentage is identical.
What to do with this
Take one position and write the planned loss, a worse-execution loss, and the consequence if related positions fall together. Keep hypothetical calculations separate from the actual records in your risk review. The specific 2015 instrument, size and control changes remain for me to add before this piece is published as a full scene.