Using the BidSize Function for Real-Time Market Data

The BidSize function in MarketXLS provides quick access to the quantity of shares (or contracts) available at the best (highest) bid price for a given symbol right inside Excel. Whether you are tracking equity or option symbols, this function helps you gauge immediate market interest by showing how many shares or contracts buyers are seeking at the current top of the order book. With BidSize, traders and analysts can monitor supply and demand levels efficiently, aiding quicker decision-making and potentially improving execution strategies.

Why Use This Function?

• Gain quick insight into market depth: See at-a-glance how strong the buying pressure is.
• Validate liquidity for entries and exits: Determine if a symbol has sufficient buyers before placing larger orders.
• Monitor option liquidity: Works with option symbols to report complete or partial data if available.
• Automate workflows: Build watchlists or trade models that automatically refresh bid size data without manual effort.

How to Use in Excel

=BidSize("SYMBOL")

• Enter the function in a cell and replace "SYMBOL" with the desired ticker or option identifier.
• Press Enter to retrieve real-time or near real-time bid size data (depending on your subscription).
• If a symbol is invalid, the function returns "NA."
• If the data is currently refreshing, you may briefly see "Refreshing" before the final value is displayed.

Parameters Explained

• “Symbol” can represent stocks or options (e.g., AAPL, MSFT, SPY231215C400).
• If the license is invalid, the function may also return “NA.”

Example Usage

Basic Examples

1. Stock Ticker Example
   In cell A1, type:
   =BidSize("AAPL")
   This will return the number of shares being bid for Apple Inc. at the current best bid price.

2. Another Equity Example
   =BidSize("MSFT")
   Displays the best bid size for Microsoft.

3. Invalid Symbol Example
   =BidSize("XYZINVALID")
   Returns “NA” when the symbol is unrecognized or the license is not active.

Advanced Scenarios

1. Tracking Option Bid Size
   For an option symbol like SPY231215C400:
   =BidSize("SPY231215C400")
   If the option data is available, this function returns the contract bid size. If data isn’t found, it shows “NA.”

2. Integration with Watchlists
   Place multiple =BidSize() formulas in a table of symbols to track real-time changes in individual cells. This setup is particularly useful for screening liquidity across numerous tickers.

3. Combining with Other Excel Functions
   Use IF() statements to watch for “NA” or “Refreshing” states. For instance:
   =IF(BidSize("MSFT")="NA", "No Data", "Available")
   This approach helps preserve the flow of your trading models or dashboards.

Common Questions and Troubleshooting

1. Why am I getting “NA” for some symbols?
   • The symbol may be incorrect or unrecognized.
   • You may not have a valid MarketXLS license or it has expired.
   • The API could not locate bid size data for that specific instrument.

2. Why does it sometimes show “Refreshing” instead of the numeric size?
   • The function uses a caching mechanism. When data is updating, it briefly displays “Refreshing” until fresh data is retrieved.

3. Does this provide Level II market data?
   • No, it only provides the top-level best bid size. Deeper order book details are not included.

4. Can I use this function for non-US markets?
   • Currently, usage typically centers on US symbols. If your MarketXLS plan includes additional market support, the same syntax applies.

Remember:

• Consistent, accurate symbols are crucial for correct data.
• Bid size can fluctuate rapidly, so real-time updates depend on your MarketXLS subscription tier.
• Use the function with other MarketXLS formulas for deeper analytics on liquidity, volume, and price action.