i'm quite sure the general directive to the broker is "buy up to...

i'm quite sure the general directive to the broker is "buy up to 135m shares over the next 12 months"; nothing more, nothing less, because ICI can't give them an edge, provide the broker with "tips" aka insider information/instructions on timing the market to get the cheapest shares. there's a body of rules & regulations that govern how SBBs work; like what the broker's budget is, type of buy-back, how much they can buy per day/etc as well as price. there aren't other instructions from ICI like when to start & stop buying because that would defeat the purpose of appointing/paying a broker in the first place; it's the broker's job to monitor the market, as a third-party, to determine how to achieve the best outcome for the company/shareholders, which is to buy as many shares paying as little as possible for them, & eliminating conflicts of interest as their position is neutral, having the same information as the market

i know SBB is very complicated to comprehend @crazydave1942 is proof of that