A picture is worth a thousand words...
Well, numbers can tell you all sorts of things but often you can glean more info by simply looking - a chart can show you what the share price has been doing. Is it constantly rising or constantly falling?
Does it go up and down like a Yoyo really rapidly or is this process stretched out over time?
A stock that is continuing to rise looks like it could be a winner - the news articles will indicate whats going on and that could help decide if it's worth investing.
Yoyo'ing all over the place could be risky - a short term investment like this could drop in value very fast but equally rise in value very fast - you'd have to time your purchase to make the most of it
Stock that is dropping in price is probably one to avoid - unless it's started to gain exposure again in which case perhaps it's time to buy low and sell high when it's price has gone back up.
Now - imagine looking at a sea of numbers and trying to come to the same conclusion...