For certain tokens, depending on the market depth, buying some can radically affect the price direction temporarily. Before I bought ASS the price was down 30% over the previous 24 hour period but then jumped up to +153% after buying 1000 ASS.
Looking at one of the tokens I created GOD the lowest bid is currently 0.000001 STEEM and the lowest selling price is 75,000 GOD for 0.000088 each and after that is 0.000089 each for 20,000 GOD. If someone right now as I am writing this paid asking price and bought all 95,000 GOD for 8.38 STEEM the price would jump up to the current third lowest selling price of 0.00066 STEEM. All it would take currently to pump my GOD token up 750% is 8.38 STEEM which is currently around $1.26 USD.
This is just to demonstrate the math of how a "pump" can occur on steem-engine.com occasionally. Purposely pumping my GOD token would be monetarily unethical. I started a mad scientist hivemind community so I am more about playing god or at least being more Nikola Tesla than playing J.P. Morgan.