No, Asset Price Movements Are Not Normally Distributed, No Way, No How

The Swiss National Bank's announcement that a weak Swiss franc was in Switzerland's interest, and that it stood ready to sell unlimited quantities of Swiss francs to resist future appreciation, caused a 20 standard deviation daily decline in the value of the franc.

The odds of such a thing happening under a Gaussian normal distribution are less than 1.25 x 10^-89.

That's odds of 80000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000:1