The bucket pattern is used for efficient paging by storing multiple trades in an array within a single document. A reasonable bucket size of 1000 trades can display history from any page quickly and efficiently, reducing the number of documents that need to be fetched. Data insertion into buckets can be done using an update statement with `$push` and `$inc` operators, which add new trade history and increment the count field atomically. The `upsert` modifier ensures that a new document is created if no bucket exists or contains less than 1000 trades. This approach has limitations, such as gaps in data when removing trades, but can be an effective solution for many use cases with excellent performance.