Weight of money (WoM) is the comparison between the money queued on each side of an exchange market, close to the current price. Traders usually add up the money at the best three back prices and the best three lay prices and read a big imbalance as pressure on the price. It is a reading of offers, not bets: any of that money can be cancelled before anyone takes it.
Reading weight of money on a Betfair ladder
The ladder is easy to read backwards. Money in the back column is offered by layers, and it is what a backer can take; money in the lay column is offered by backers, and it is what a layer can take. With illustrative amounts for one runner:
| Back price | Layers' money waiting | Lay price | Backers' money waiting |
|---|---|---|---|
| $4.20 | $310 | $4.30 | $260 |
| $4.10 | $520 | $4.40 | $410 |
| $4.00 | $880 | $4.50 | $350 |
| Best three | $1,710 | Best three | $1,020 |
Layers' money is 1,710 / (1,710 + 1,020) = 62.6% of what is waiting near the price. The usual reading is a drift: layers who want to get on now have to take the backers' prices at $4.30, $4.40 and $4.50, and with only $1,020 there, it would not take much to push the price out. More backers' money than layers' money is read the opposite way, as a price likely to shorten.
Why it misleads in Australian racing at times
Three things make the reading on an Australian race weaker than it looks.
- Much of the money is elsewhere. Racing NSW wrote in 2017 that the larger wagering operators took the majority of wagering on NSW meetings, so news and big bets can show up first in bookmaker prices, with the exchange following. A price can move against the visible money because the move started somewhere the ladder cannot see.
- Early books are thin. Hours before a race, the money near the price can be a few small offers, so one punter's order is most of it and the percentage swings on very little. The same figure close to the jump rests on more money, and means more.
- Offers are not commitments. Nothing stops a $1,000 offer being cancelled a second before someone takes it.
Before giving any reading weight, check total matched, which counts money that has actually traded, and the back lay spread, which shows how far apart the two sides are. Bookmaker names are trade marks of their owners. B337 is not affiliated with them.
How spoofing distorts it
Spoofing is placing money you do not intend to have matched, to make one side of the book look heavier.
Add one illustrative order to the same ladder: $1,500 of backers' money at $4.40, one tick behind the best lay price of $4.30, where a layer would have to take the $260 at $4.30 first. Backers' money near the price becomes 1,020 + 1,500 = $2,520 against $1,710, so their share jumps from 1,020 / 2,730 = 37.4% to 2,520 / 4,230 = 59.6%, and the usual reading flips from drift to shorten.
If the order is pulled before anyone lays into it, nothing traded and the signal was never real.
Signs of a spoof:
- a large order a tick or two from the best price that moves away as the price comes towards it;
- money that appears and disappears without anything trading;
- a reading that swings hard while the spread and the traded prices barely move.
Using it alongside other evidence
Treat weight of money as one input, read beside price history and the money already traded. A runner whose price keeps lengthening while the book looks heavy with backers is telling you the visible money is not the money that matters; the drifter entry covers what a lengthening price does and does not mean.
The minutes before the jump are where traders lean on this reading most, and pre-race trading covers that window and its limits. How backing and laying fit together is in the lay betting guide.
B337 places no bets on the exchange. Its Terminal shows prices from 40+ bookmakers across racing and sports with Betfair back and lay and price history beside them, so a move on the exchange can be set against the bookmakers that price the same race.
Risk: Betting involves risk. Weight of money describes offers that can vanish, prices can move against it, and there is no guarantee of profit from reading it. See responsible gambling for limits and support.