There was a prolonged dip in the price in this weekend, and I was wondering if this had an effect. There've been many large Bitcoin transactions recently, especially on Bitcoin Black Friday. For instance, Amagi Metals apparently sold $900,000 worth of gold and silver for Bitcoin using Bitpay as their processor.
That alone is currently a significant volume to liquidate. Enough to move the price 4-5% on some exchanges. Bitpay only takes a ~1% fee, but I assume their exchange rate is padded to absorb some of that risk. They may also sell bitcoin off the exchanges, which doesn't have a direct impact on the price.
BitPay takes 1% if you're on the free plan. Otherwise, there's just a monthly fee (well, you need to be on the $300/mo plan to get unlimited volume otherwise you're limited to $300,000/mo and $10,000/transaction)! https://bitpay.com/pricing
The payment processor (eg BitPay) takes that on. Markets are still razor thin by fiat currency standards, but are 10x to 100x thicker than a year ago. For example, buying 1.5 million USD instantly would raise the price about 4% (using just one exchange, Bitstamp)
Sometimes, a purchase or a sale of Bitcoins in the hundreds can take the market up and down by as much as 5-10% depending on the order book. I'm not sure if anybody has noticed, but Coinbase bases the price on quantity as they need to place a market order and then you depending on Bitstamp's order book state at the moment, the price difference can be huge! How are you gonna explain to consumers that they have to pay more, because they're placing a bigger order?
Since most transactions are on the order of 1/1000 of a Bitcoin, it's useful to rephrase what you said as: around 150 million mBTC are being transacted (on the blockchain) per day.
That alone is currently a significant volume to liquidate. Enough to move the price 4-5% on some exchanges. Bitpay only takes a ~1% fee, but I assume their exchange rate is padded to absorb some of that risk. They may also sell bitcoin off the exchanges, which doesn't have a direct impact on the price.