I have same algo tested in dialy mode and minute mode as well.
The results are very different.
I have same algo tested in dialy mode and minute mode as well.
The results are very different.
Yagnesh, check out this thread: https://www.quantopian.com/posts/differences-between-minute-and-daily-backtests
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.
@Alisa, as the fill price of market orders puzzles many people and questions are periodically asked, would it be possible to improve the documentation of Slippage Models in the Help section to include how the fill price is calculated? I believe including the answer you gave in here would be enough.
Many people, like me, start backtesting their algorithms without slippage model and introduce it later (one problem a time). They erroneously believe that setting slippage to 0.0 does the trick, but it doesn't. Slippage documentation says: "Slippage is where our backtester calculates the realistic impact of your orders on the execution price you receive". That's not true, Slippage calculates the impact of the orders on the price of the next bar, where "next bar" can be next minute or next day bar, depending on the backtest settings.
It's a minor thing to document, but it changes completely what to expect from the backtest.
Also, not only the price used to fill the market orders is the next bar price, it is also the close price. While I agree with the intent of making the backtest more realistic, I believe that using the close price is too pessimistic (1 minute before an order reach the market?). It would be nice to have a new slippage class (together with Fixed Slippage and Volume Share Slippage ones) similar to this one , that allows to use open price to fill orders.
Please Alisa, let me know what you think regarding my comments. Thanks.