  The financial market is a particularly challenging playground for deep
reinforcement learning due to its unique feature of dynamic datasets. Building
high-quality market environments for training financial reinforcement learning
(FinRL) agents is difficult due to major factors such as the low
signal-to-noise ratio of financial data, survivorship bias of historical data,
and model overfitting. In this paper, we present FinRL-Meta, a data-centric and
openly accessible library that processes dynamic datasets from real-world
markets into gym-style market environments and has been actively maintained by
the AI4Finance community. First, following a DataOps paradigm, we provide
hundreds of market environments through an automatic data curation pipeline.
Second, we provide homegrown examples and reproduce popular research papers as
stepping stones for users to design new trading strategies. We also deploy the
library on cloud platforms so that users can visualize their own results and
assess the relative performance via community-wise competitions. Third, we
provide dozens of Jupyter/Python demos organized into a curriculum and a
documentation website to serve the rapidly growing community. The open-source
codes for the data curation pipeline are available at
https://github.com/AI4Finance-Foundation/FinRL-Meta
