Yes, APMEX shows the spot price for paper traded silver. But paper silver is just money moving around and people thinking that they own "Silver". The problem with paper Silver is when investors start demanding physical delivery. Historically, only about 1% of investors holding paper request physical delivery. That's always worked in the past, as there was enough supply for the traders to get silver for those demanding delivery. But in today's market, physical Silver is scarce and is staring to approach unobtanium status.
With an increasing number of investors demanding physical delivery, the traders aren't able to actually deliver physical Silver to those requesting delivery. That's why those paper contracts have a Force Majeure clause, which is a weasel clause that allows traders to weasel out of the contract by paying the investors back, but at a price they select, which can be lower than spot price. IMO, the true value of Silver is what you actually have to pay to acquire a physical ounce. Spot prices are fun to watch and use as a gauge, but they're meaningless if you can't actually purchase an ounce of Silver at that price.