The HTML page only contains the first 20 posts. You have to get more using posts.json, for example GET https://forum.snap.berkeley.edu/t/9676/posts.json?post_ids[]=98011&post_ids[]=98012&post_ids[]=98014&post_ids[]=98015&post_ids[]=98016&post_ids[]=98017&post_ids[]=98018&post_ids[]=98019&post_ids[]=98020&post_ids[]=98021&post_ids[]=98022&post_ids[]=98023&post_ids[]=98024&post_ids[]=98025&post_ids[]=98026&post_ids[]=98027&post_ids[]=98028&post_ids[]=98030&post_ids[]=98031&post_ids[]=98032&include_suggested=true