Bill Ackman swears to learn from 2015, loses another 14% to start the year

Pershing Square Capital Management billionaire manager Bill Ackman had a great year in 2014 but the past 13 months have shown that luck is as much of the equation as skill.

The biggest hit came from Valeant but pretty much everything he owned struggled. After his fund lost 20.5% in 2015, he's taken another hard hit to start 2016, with his portfolio down 14%.

Listen to this endearing turn of phrase:

"We do not believe that our investment performance in 2015 was primarily due to unforced errors, but rather due mostly to the market's reappraisal of our holdings without a corresponding material diminution in their intrinsic value," he writes.

Here is his letter to shareholders.

Aside from excuses, he goes into a long rant on index funds and it's an important point.

"When capital flows reverse, index fund returns will likely decline, reducing investor interest, further increasing capital outflows, and so on. While we would not yet describe the current phenomenon as an index fund bubble, it shares similar characteristics with other market bubbles," he writes.

In FX, he talked about puts on the Saudi Riyal and Chinese yuan but warned they're expensive.