I have downloaded a complete list of all NYSE stock symbols from the NASDAQ website here. As it turns out, many of these symbols are not recognized by the yahoo finance page. In particular, there are ticker symbols that use "^" and "/" (eg. VALE/A or CTZ^A) which yahoo finance does not recognize.
I've just noticed that, vice versa, yahoo itself has some conventions (eg. adding ".F" or ".SG" to the symbols) that don't appear on the NASDAQ list I downloaded. Why this incompatibility? Does anyone know how to "translate" the ticker symbols between the NASDAQ list and the yahoo finance webpage? I thought these symbols were supposed to be a sort of universal identifier.