You can't withhold info from the ASX, you must report an...

You can't withhold info from the ASX, you must report an announcement as soon as you have that info. Once that has been given to the ASX, they will determine if it's price sensitive. In this case, there was to be an update on Smartcough C and due to being forced to give that info as they received it, they decided to go into a voluntary trading halt.

However, due to the listing rules, you cannot have a trading halt for more than 2 trading days and as such, you can apply voluntarily to suspend the trading of shares. You apply to the ASX for this suspension if you can give the reasons, timeline and events of which will happen after suspension.

In respect to this company that would be price sensitivity of due results, August 9th and release of said "top line" results from the study. Nothing about the above is unusual and particularly for biotech stocks, trading halts and suspensions happen all the time simply due to the nature of the industry. Potentially hundreds of people are involved in the data gathering and research process and as such, a substantial amount of people will hold information that could see a stock gain or lose multiples of its value.

In short, there is nothing remotely unusual about the suspension and people need to take a break and come back next week.