The benchmark includes re-invested dividends. Your algorithm sits on a lot of cash that comes in from dividends. I added a "record" line to your algorithm so that you can monitor your cash. If you re-invest your dividends, you'll get a lot closer to benchmark.
As a bit of a tangent, I'll note that you'll never get exactly the same result. The benchmark has the privilege of "buying" at the open price, because the benchmark is always in the market. Your algorithm has to wait for your order to process, so it actually only goes long at the start of the 2nd bar. But that is a minuscule effect compared to the dividends.
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