Table subtitle in Stata estout to LaTex-table

I am trying to write table "subtitle" text that sits on top of the table, below the caption. I am using esttab in Stata to get the output below, but I am unable to make the aforementioned changes.

Further, I am trying to change the font size of the table caption. Can anyone help me with this?

defsym#1{ifmmode^{#1}else(^{#1})fi}
begin{adjustbox}{max
width={textwidth},caption={Descriptive statistics, exchange type. Purchase only},nofloat=table}
begin{tabular}{l*{2}{ccccc}}
hlinehline
hlinehline
end{tabular}end{adjustbox}