i didnt study alot for economics ( most of the concepts i got first time around in class) , one or two i looked at again after class but that was about it, my only real study for economics was for the assessment tasks, and like 2 weeks before the trials and hsc i would try to bash as much content into my head as possible, the concepts in economics i thought were fairly easy
most of my study time went into my maths and science
dont worry about that topic, it doesnt even show up in the hsc course, all you need to know is that the share market is extremely volitile ( because of, i think they refer to it as herd behaviour, when something goes wrong ( e.g. exchange rates fall suddenly), everyone rushes to sell their currency to aviod further losses) and that the share market acts a means for businesses to obtain money for their operations. and the difference between debt financing and equity financing , and the advantages/disadvantages of those.
got any questions with what i said are anything feel free to mesage back