Custom Beta Thirty Days Formula in Excel

Understanding Custom Beta Thirty Days

The Custom Beta Thirty Days formula helps you quickly measure how volatile or risky a particular stock is relative to a benchmark index—commonly the S&P 500 ETF (symbol “SPY”). By evaluating price movements over the last 30 calendar days, this function provides valuable insight into short-term market sensitivity.

• Helps assess short-term volatility.
• Useful for risk management and portfolio optimization.
• Simplifies comparative analysis against a default or custom benchmark.

? Pro Tip: Use this formula when you need a snapshot of a stock’s short-term beta without manually adjusting date ranges.

Syntax and Parameters

Use the CustomBetaThirtyDays function to return the 30-day beta for a given symbol. You can specify a secondary benchmark and a return period if needed.

=CustomBetaThirtyDays(symbol, [benchmark_symbol], [period])

Return Value:
• Returns a numeric beta value representing the stock’s volatility relative to the benchmark.
• If the ticker or benchmark symbol is invalid, the function returns "NA".

?? Note: This formula requires a valid MarketXLS license. If your license is invalid or expired, it will return an error.

Examples and Usage

1. Calculate default 30-day beta against SPY (daily):

   =CustomBetaThirtyDays("MSFT")

2. Calculate 30-day beta using a custom benchmark (daily):

   =CustomBetaThirtyDays("MSFT","AAPL")

3. Calculate 30-day beta using a custom benchmark on a monthly basis:

   =CustomBetaThirtyDays("MSFT","AAPL","monthly")

4. Calculate 30-day beta on a weekly basis:

   =CustomBetaThirtyDays("MSFT","AAPL","weekly")

• Quickly compare a stock’s short-term volatility vs. an alternate benchmark.
• Use daily, weekly, or monthly returns depending on how frequently you want to measure volatility.

Common Questions

1. What happens if I use an invalid symbol?
   If the symbol is invalid or not recognized, the function returns "NA". Make sure your symbol string is correct.

2. Does this function accept custom date ranges?
   No. This function is preset to calculate beta over the last 30 days automatically and does not accept start/end dates as parameters.

3. Why do I see "NA" or no data?

   • Check if your MarketXLS license is active.
   • Verify you have an internet connection.
   • Confirm the symbols are correct.

4. What are the related functions?

   • Total Dividends Paid Between Two Days In The Past
   • Stock Return Seven Days
   • Stock Return Fifteen Days
   • Stock Return Thirty Days

? Pro Tip: For performance considerations, large data queries may be cached. Allow a few seconds for results to appear when using new or infrequently accessed symbols.