BTW a question regarding HN ranking. This story has now 26 points after 41 minutes and is placed 83th (was 30th when I entered) whereas a story posted 4hrs ago

BTW a question regarding HN ranking. This story has now 26 points after 41 minutes and is placed 83th (was 30th when I entered) whereas a story posted 4hrs ago ("Mattermark Index: Y Combinator Summer 2013 Companies") has 27 points and is on the front page. Can someone explain that? I though that new stories with similar score should be much higher. Are there negative votes on submissions possible (and I don't see them due to karma thresholds)?