If strep bacteria causes the infection, it can remain contagious for up to 2 weeks without treatment. However, antibiotics can shorten the contagious period and li â¦ mits to about 24 to 48 hours once the therapy starts.     http://health.top54u.com/post/How-Long-is-Tonsillitis-Contagious.aspx.
Calculate Options Implied Volatility in Excel. Implied Volatility Function: Returns the annualized volatility of an underlying security implied by the market price of a European call or put option on that security, based on Black-Scholes valuation. Description of parameters.
Volatility tends to decline as the stock market rises and increase as the stock market falls. When volatility increases, risk increases and returns decrease. Risk is represented by the dispersion of returns around the mean.To find out how the VIX measures volatility, read Getting a VIX on Market Direction.). Volatility works well to help identify market bottoms based on high volatility. For long-term investors, it also does a pretty good job of helping to identify that the stock market is at or near a top, when volatility is very low.