Understanding the Large Bid Size Alert

This alert reports when a stock has an unusually high number of shares on the best bid. This is a very short term alert aimed at very fast, experienced traders.

We only generate this alert for stocks with an average daily volume of less than 3,000,000 shares per day. If a stock typically trades less than 1,000,000 shares per day we require a bid size of 6,000 shares or greater to generate an alert. Otherwise we require a bid size of 10,000 shares or greater to generate an alert. We also have additional filters to prevent a stock from reporting this alert too often. For example, if the best bid for a stock is 20,000 shares at $10.00, then someone adds a bid of 100 shares at 10.01, the 20,000 shares still appear in the order book. When the 100 shares go away, and the best bid returns to the 20,000 shares at $10.00, we do not report another alert.

If we report a large bid size, then the size grows even larger, we typically report another alert. The message for that alert is labeled "(Size increasing)".

If a stock is showing a large bid size, and the price changes but the size remains large enough, we may report an additional alert. The message for that alert is labeled "(Price rising)" or "(Price dropping)". This message only applies to large size. For example, if we see a 20,000 shares on the bid at $10.00, we report an alert. If the best bid changes to 100 shares at $10.05, we report nothing. If the best bid then changes to 15,000 shares at $10.02, we report a second alert, labeled "(Price rising)".

If a large bid is dropping, this makes for a stronger alert. If a large bid is rising, this may be a "head fake"; someone may be trying to trick you by showing large size in one direction, while slowly buying or selling in the other direction. In either case, we report an alert.

The bid and the ask are two completely separate alerts. The size or price of the bid does not influence the Large ask size alert. The size or price of the ask does not influence the Large bid size alert.

Default Settings

By default, this alert will appear when stock that is trading 1,000,000 shares per day has a bid size of 6,000 shares or greater. Otherwise a bid size of 10,000 shares or greater is required generate an alert.

Custom Settings

For 'Large Bid Size' alerts, you have the option to use an alert specific filter. This filter is located immediately to the right of the corresponding alert and is always optional. You can decide to leave it blank if you want to receive more alerts, or you can fill it in to restrict the number of alerts you receive.

This filter allows you to specify the quality of the alert. When you set a higher number for this filter, you are telling the alerts server to display only alerts that meet a higher quality standard, resulting in fewer alerts being shown.

When setting an alert for 'Large Bid Size', you can specify the minimum number of shares on the best bid. If a stock is showing fewer shares when the alert is reported, you will not see the alert. We do not smooth or average this value; all that matters is the value at exactly the time the alert was reported. If you leave this field blank, you will see the most alerts. Some alert types have minimums built into them. You can also set minimums for the entire window. An alert must pass through all of these filters to be displayed.

Description Column

The description column of your scan will give more detail on the alert. It will include notes such as "size increasing" or "price rising" if a bid size or price continue to increase after the initial alert.

Quality Column

Add the quality column to a scan using the 'Large Bid Size' alert to see the number of shares on the bid.