The posts on the trending page are almost always there due to the author purchasing votes using bid-bots (or similar vote buying services through smartsteem etc).

Essentially the author uses SBD or Steem to pay for the post payout. The main benefit is promotion / marketing, i.e. getting their post lots of views.

There may also be a profit or loss, largely dependent on how the Steem price moves over the seven day payout period and the competitiveness of the bid-bot vote auction. However this profit or loss is much smaller than the post payout you see on the Steemit site.

One way to check the bid-bot use is to switch across to the busy.org platform. By clicking on the number of upvotes you can see all the voters for the post and the dollar amounts of the upvote. You can then check the voters against the steembottracker to see which are bid-bots.

For example on the current post at the top of trending the top voters are appreciator, smartsteem, buildawhale, rocky1, upme, postpromoter, therising, isteemd, upmewhael, and jerrybanfield. These are all bid-bots or vote purchasing services.

Of the total $780 post payout on that trending post the highest vote amounts which do not come from a vote-purchase are $1.75 (someone hunting curation rewards by voting before the bid-bots) and $0.48. Without the vote purchasing the post would make only a few dollars maximum.