How important is upward trend?

<p>I'm just wondering. I had a bunch of B's as a Freshman, but since then I've had only A's in all of the toughest classes available, while taking a dual curriculum that has 9+ hours of class a day. I was wondering how significant an upward trend is when the overall GPA is low (for an Ivy. A- type.)</p>

<p>Thanks</p>