Something I just figured out. If you go to Results and click on the date (03, today), there will be an explanation of what brought on the yield for that day. Here is the report from Admin for today:
MONDAY 3RD MARCH 2014

2.28%

With the whole MtGox debacle behind us, the Bitcoin industry seems to finally be making a major recovery. At the time of writing this, the price on Bitstamp is up more than $100, and other markets have seen similar increases. Furthermore, the volatility in the prices has brought back the arbitrage opportunities that we're accustomed to seeing between the various exchanges. During periods of rapid price increases or decreases, we find that there are always ample opportunities on the smaller markets, where the prices typically lag the global average. In addition to the profits made from the smaller exchanges, we were also able to benefit from having moved a good portion of our fiat to BTCe over the weekend. The total result for today is 2.28%

Very nice feature. This to me is Adam's way of communicating with his investors, which some have believed he does not.
Love this company and hope it goes on for years.