Market sentiment and the speculative sentiment index
Every release lands on a market that already has an opinion. That opinion decides how far the reaction goes — and often which way.
Lesson 11 of 12.
Sentiment is not psychology
Two things are easily confused and the source separates them on its first slide.
Trader psychology is about you — the discipline to take the loss, the impulse to add to a position that is wrong, the tendency to close a winner early. It is real and it is not what this lesson is about.
Market sentiment is about everybody else — what positions are already open, which way they lean, and how strongly. It is a measurable property of the market rather than a state of mind, and it is the third of lesson one's three causes.
The source is direct about why it matters: one of the most important steps to success in this market is analysing and anticipating the behaviour of the other traders in it. When sentiment is strong, a move that starts for a fundamental reason keeps going for a positional one — and when it is extreme, it can reverse the fundamental entirely.
Right about the number, wrong about the trade
The clearest evidence in the deck is two rate rises, and both behave the same way.
After a rate rise in Canada, the pair fell 130 pips — the textbook reaction — and then rose 300. After a rate rise in the United States: 70 pips down, then 200 up.
In both cases the fundamental analysis was correct, the initial move confirmed it, and anyone who held that position through the following session lost more than they had made. In both cases the reversal was more than twice the size of the move that preceded it.
The mechanism is positional rather than economic. Everybody who wanted the trade had it on before the announcement. Once the announcement confirmed them, there was nobody left to buy — and the only remaining flow was those same traders taking profit. A crowded correct position unwinds harder than a wrong one, because everyone leaves through the same door at the same time.
What the sentiment index measures
A market sentiment index — the speculative sentiment index, or SSI — answers one question: at this moment, how many traders hold a buy position in this pair and how many hold a sell?
It is published as a ratio. The source's example is EUR/CHF at −5.94, which reads: for every one open sell position in the pair there are 5.94 open buys. Nearly six to one, on one side.
Two things it is worth being precise about, because the number is easy to over-read.
- It counts positions, not money. Two hundred small longs and one very large short show as a strong long reading, and the short may be the one that matters.
- It is one broker's book, not the market. It is a sample — a large and useful one, but a sample of retail traders at one firm rather than a census of the market.
Why it is read against the crowd
The source describes the index as generally a contrarian one: when you can see how many positions are open in each direction, it is usually better to look in the opposite direction to the crowd, taking the shape of the price chart into account.
The reasoning is the same as the reversal above. Every open position is a future order in the opposite direction — a long must eventually sell, whether at a target or at a stop. So a heavily one-sided book is not demand; it is pending supply. When nearly six traders in seven are long, most of the buying has already happened.
The source's own examples run in both directions, which is what makes them worth rebuilding: AUD/USD falling from 1.06 toward 0.94 with the ratio of open positions moving against the fall; open sell positions rising sharply through a historic EUR/USD rally; GBP/USD and USD/JPY net positioning plotted against price; open buy volume in EUR/USD; NZD/USD against its position book.
The pattern in all of them is the same. As a trend runs, the crowd increasingly bets against it — and the crowd is most one-sided at the point the trend is closest to ending.
How to use it without being caught by it
The contrarian framing needs one qualification the source does not give, and it is the difference between using this well and using it expensively.
A crowded position is a reason for caution, not a signal. Sentiment can stay extreme for a long time, and "everyone is long" is true for most of the way up a trend as well as at the top of it. Used as an entry trigger it will have you selling strength repeatedly.
What it is genuinely good for:
- Sizing. If you are about to take the same side as six traders in seven, take less than you otherwise would. You are not wrong; you are crowded.
- Expecting the reversal. A correct fundamental view plus an extreme reading is the setup from the first section — take the move, and do not hold it through the session after the release.
- Confirming exhaustion, with something else. Extreme positioning plus a fundamental that has stopped improving is a far better argument than either alone.
- Explaining a move that made no sense. When a currency falls on good news, the positioning is usually where the explanation is.
What to take from this one
Three things:
- Sentiment is what everybody else already holds. It is measurable, and it decides how far a correct forecast actually travels.
- Both of the source's rate-rise examples reversed by more than twice the initial move. A crowded correct position unwinds harder than a wrong one.
- Read the index against the crowd, but use it to size and to time an exit rather than to enter. Extreme is a condition, not a trigger.
Next: putting all twelve together
Eight decisions in order — instrument, market, timeframe, bias, size, hedge, hedge timing, second instrument — and the dashboard that holds them.