  We develop a theory of securities price formation and dynamics based on
quantum approach and without presuming any similarities with quantum mechanics.
Disorder introduced by trading environment leads to probability distribution of
returns that is not a smooth curve, but a speckle-pattern fluctuating in both
price coordinate and time. This means that any given return can at times
acquire a substantial probability of occurring while remaining low on average
in time. Still, due to local character of order interaction during price
formation the distribution width grows smoothly, has a minimum value at small
time scale and a square root behavior at large time scale. Examples of
calibration to market data, both intraday and daily, are provided.
