How Does a High Volume of RBF Transactions Affect the Overall Size of the Mempool?

A high volume of RBF transactions can temporarily increase the mempool's overall size and volatility, but the effect is generally manageable under current policies. Each RBF transaction introduces a replacement, which briefly exists alongside the original transaction until the original is evicted.

While this replacement process adds data, the net effect is often a churn rather than a sustained growth, as one transaction is replaced by another. However, constant replacement can increase the processing load on nodes.