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.
What is 'Volatility'. Volatility is a statistical measure of the dispersion of returns for a given security or market index. Volatility can either be measured by using the standard deviation or variance between returns from that same security or market index. Commonly, the higher the volatility, the riskier the security.