that is what i figured.
as i said you are mistaking the meaning of opening price. these prices (market open and market close) are prices of the filled orders not open orders.
this is the definition of it:
http://www.wikinvest.com/metric/Opening_Price which may help you better.
also i found this reply which i think can help you understand things a lot better than i can explain with my English skills (or lack thereof)
http://money.stackexchange.com/a/4526you only have to remember than the difference between a stock market and an altcoin market is that stock market closes on a specific time and opens in the morning each day while altcoin market never closes.
Here's an example output, where you can see that the market close of 11:45:00 is not market open of 12:00:00, makes sense?
******************************
Time: 8/31/2016 11:45:00 AM
Market open : 0.01361091
Market close : 0.01384994
Market change : 1.76%
******************************
Time: 8/31/2016 12:00:00 PM
Market open : 0.01375
Market close : 0.01394847
Market change : 1.44%
let me give you some times for the above:
11:45:20 --> someone buys XMR at
0.0136109111:45:50 --> someone buys XMR at 0.013725
11:47:35 --> someone buys XMR at 0.014500
11:50:50 --> someone buys XMR at 0.018521
11:55:20 --> someone buys XMR at 0.013927
11:58:00 --> someone buys XMR at
0.01384994nobody buys anything until
12:01:10 --> someone buys XMR at
0.01375....
....
12:14:20 --> someone buys XMR at
0.01394847{the numbers of hypothetical but close to reality}