Essentially the Bullboards are structured as a topical conversation where a member creates a topic that is the first post and others can reply directly to the original post or to others comments further down the thread. Replies to a post will have a "Re" added to the subject line.
However on Stockhouse we have historically favoured the flat view of that same information and the navigation defaults to this "Flat" view of the content. This is where all posts, regardless of context of the conversation are shown in a chronological order of when they were created. This means conversations from different topics are shown mixed together.
That flat view can be shown newest to oldest and oldest to newest, depending on what you are looking for.
In addition to flat views you can also use "threaded" view to see the content in the context of the conversation.