Coalescing Ring Buffer 1.1.3 Released

You can now download the new coalescingRingBuffer-1.1.3.jar and



Bitcoin Volatility

A repeated criticism of bitcoin is its high volatility so I decided to have a look myself. This is the rolling 30 day annualized volatility of bitcoin measured in USD on over the last year.


So while it is still over 100%, it is lower than its peak in December and that was lower than the peak in April. My guess is that as the ecosystem continues to grow we will see this trend of lower volatility continuing. Hopefully not to the point where it becomes boring though 🙂


  1. Download prices from for the last year + 30 days
  2. Compute the daily logarithmic returns on the closing prices for each day
  3. Compute the 1 day volatility (STDEV function in libre office calc) by using the last 30 daily logarithmic returns
  4. Annualize the 1 day volatility by multiplying by the square root of 365

JavaZone 2013 Talk

Here is the 10 minute lightening talk I gave at JavaZone 2013:

How to use TDD to create a thread-safe, lock-free, high-performance cache by using knowledge of how modern processors are designed.