When you're viewing the alexa info for a domain, click the "See Traffic Details" link.
If the domain is in the top 100,000 it will have a nice graph that is the best way of telling if a site is on the rise or decline.
Otherwise, you can check the traffic rank below the graph.
Traffic rank:
Today: 233,357
1 wk.: 226,467
Avg. 3 mos.: 462,459 <--- your current Alexa ranking
Avg. 3 mos. Change: 3,397,290
What these numbers mean -
Your current rank (462,459) is a three month average of your daily traffic ranking. For example, your ranking for today only is 233,357. If your traffic were to remain the same as today for the next three months, your Alexa ranking would rise to around 233,000.
Also telling is your "Avg. 3 mos. Change". This shows that three months ago, your Alexa ranking was in the mid 3,000,000's.
So I can deduce that your site is on the rise trafficwise.