As Ernesto noted, the leaderboard has successfully updated for all contests and should be back and updating as normal moving forward.
I'd like to give you some background as to the cause of the problem so you have some clarity as to what was happening behind the scenes. The root cause of the problem was that the benchmark data used by the leaderboard calculations began to fail. It failed unexpectedly because it was using pyfolio for the data and pyfolio was relying upon the Yahoo API for benchmark data. Using Yahoo data makes sense within the context of pyfolio since it is open source and the Yahoo data was freely available.
As many of you likely know, the (undocumented) API for this Yahoo data changed abruptly recently. This change caused a series of failures in quite a few of our open source libraries, pyfolio included. Once we sorted out the problems, we concluded that (of course) we needed to fix the leaderboard and that it should no longer rely upon Yahoo (or any other free API for that matter).
This part of our architecture had not previously accessed market data such as this so it was quite a bit more complex than a typical bug fix. In turn, once the development work was complete, this new code failed a variety of integration tests over the last few days, preventing it from coming out in a more timely fashion. We thought we were 'done' but our integration tests thought otherwise.
We're sorry that this bug lingered for so long. We know you invest a lot of time in the contest and your research on Quantopian and we will continually work to make the entire platform more robust, reliable and more powerful.
The material on this website is provided for informational purposes only and does not constitute an offer to sell, a solicitation to buy, or a recommendation or endorsement for any security or strategy, nor does it constitute an offer to provide investment advisory services by Quantopian. In addition, the material offers no opinion with respect to the suitability of any security or specific investment. No information contained herein should be regarded as a suggestion to engage in or refrain from any investment-related course of action as none of Quantopian nor any of its affiliates is undertaking to provide investment advice, act as an adviser to any plan or entity subject to the Employee Retirement Income Security Act of 1974, as amended, individual retirement account or individual retirement annuity, or give advice in a fiduciary capacity with respect to the materials presented herein. If you are an individual retirement or other investor, contact your financial advisor or other fiduciary unrelated to Quantopian about whether any given investment idea, strategy, product or service described herein may be appropriate for your circumstances. All investments involve risk, including loss of principal. Quantopian makes no guarantees as to the accuracy or completeness of the views expressed in the website. The views are subject to change, and may have become unreliable for various reasons, including changes in market conditions or economic circumstances.