A tip is essentially an LRU cache: https://www.ft.com/content/e6f82da0-8b4d-11e6-8cb7-e7ada1d123b1 https://www.ft.com/content/e6f82da0-8b4d-11e6-8cb7-e7ada1d1

A tip is essentially an LRU cache: https://www.ft.com/content/e6f82da0-8b4d-11e6-8cb7-e7ada1d123b1 https://www.ft.com/content/e6f82da0-8b4d-11e6-8cb7-e7ada1d12... (I first heard about this concept ages ago, but that's the first article on Google; sorry if paywalled).