The Odd Lot Short Ratio ("OLSR") is a market
sentiment indicator that displays the daily ratio of odd lot short sales
compared to odd lot buy/sell transactions.
Investors "short" a stock in anticipation of the
stock's price falling. Instead of the traditional transaction of buying
at a lower price and profiting by selling at a higher price, the short
sale transaction is just the opposite. To profit from a short sale, the
stock must be sold at a higher price and bought (covered) at a lower
price An "odd lot" short is a short sale transaction involving less than
100 shares.
Interpretation
If we could find an investor who was always wrong
and do the exact opposite of him, we would always be right! Odd lot
indicators strive to do just that. If we assume that small investors
("odd lotters") are inexperienced (and thus usually wrong), then trading
contrarily to the odd lot traders should be profit-able.
The higher the OLSR indicator, the higher the
percentage of odd lot shorts and the more likely the market will rise
(proving the odd lotters wrong). Similarly, the lower the OLSR, the more
likely a market decline.
Generally this rule (invest contrarily to the odd
lotters) has held true. Odd lotters tend to be reactive rather than
proactive. High Odd Lot Short Ratios tend to come after major market
declines (when investors should be buying, not selling) and low readings
usually come after long market advances.
In 1986, the number of odd lot shorts reached levels
that were unheard of. The explanation I have heard for this is that
specialists are placing multiple odd lot short orders to avoid the
up-tick rule which states that a short order must be processed on an up
tick. They do this on days with major declines in prices.
If this explanation is true, it drastically
complicates the interpretation of all odd lot indicators. It would mean
that the odd lot indicators show what the "littlest" guy is doing,
except when it reaches extreme readings in which case it would show what
the "biggest" guy (the members) is doing.
Example
Refer to the examples inside the explanation of the
Odd Lot Balance Index and Odd Lot Purchases/Sales.
Calculation
The Odd Lot Short Ratio is calculated by dividing
the number of odd lot short sales by the average number of odd lot
transactions for the day. (Because odd lots do not necessarily have a
buyer and a seller for every transaction, we calculate the average
number of transactions by adding the number of odd lot buy orders with
the number of odd lot sell orders and then dividing by two.)