Ann: Change in substantial holding, page-19

Hi @flashgrains
A closed period is a fixed period specified in a company's trading policy where management and key personnel are restricted from trading in the company's securities. They are generally either side of key reporting dates such as quarterlies, earning reports etc.
Key personnel can trade under specific circumstances but this needs to be approved by the board (and possibly cleared by the ASX?).
Companies generally have this information on their websites under the 'corporate governance' section. You can find BRB's here: https://www.breakerresources.com.au/wp-content/uploads/CO-PL-001-Securities-Trading-Policy_v9.pdf

a) two weeks prior to, and 24 hours after the release of the Company’s Annual Financial Report;
b) two weeks prior to, and 24 hours after the release of the Half Year Financial Report of the Company; and
c) two weeks prior to, and 24 hours after the release of the Company’s quarterly reports,

Additionally, if any Company Personnel is in possession of price
sensitive information which is not generally available to the market, then he or she
must not deal in the Company’s Securities at any time.

Closed periods are defined under listing rule 19.12 (Chapter 19)
Hope that helps,
Perdy