There are some downward pressure from the bears, as indicated by those wicks at the top of the candles. Which also suggests that there are bears in the market with their stops place above those wicks. If the bulls take control in the next few candles and take the market up, they will take out those stops and therefore those bears switch over to bull by closing or buying back their shorts, hence we will see some bigger upwards moves/spikes/larger bull candles incoming.