In looking at the chart, it's clear that the risk profiles of P&G and Baidu are very different, so assigning the same risk profile to them makes no sense. It could be argued that a 5% decline in P&G would be more of a reason to worry than a 10% decline in Baidu.
Put the Decline in Context
The reason for the decline should also play a role in how a stop order is used. I tend to be less worried about a stock that drops 9% if the broad market is dropping 8% at the same time. A 9% drop would be more of a concern in a flat market or a rising market -- but then again, maybe not.
Gold mining stocks often zig when the market zags. If you own a gold miner for that reason and it, along with all the miners, is going down in an up market, should you really sell it? In that scenario, it's doing its job.
If you believe in maintaining a diversified portfolio and if a stock you own in a sector is down an amount consistent with the rest of its sector, it probably shouldn't be sold on the basis of an arbitrary price movement.