My opinion is that some brokers manipulate the traders by manipulating the spreads.Example..I have seen FXCM with a very low spread on a pair when price is going up but if it starts ticking down the spreads get a lot wider.same thing in reverse...where my opinion comes in is that I believe that if the firms traders are predominantly in a short they give tight spreads but open the spreads if trade is starting to go against their positions.Think about it logically..if spreads are tight it encourages trading but if spread is excessively wide it DISCOURAGES trading...a simple law of the FOREX jungle.All JMHO of course
Another thing on the extra decimals Trend..,The Yen crosses...right now USD/JPY bid is 98.108 and ask is 98.133...the pipette thing comes into play on Yen crosses as well.