Hi Statalisters!

I have a time series dataset that I have set as such with the
Code:
tsset
command. I am plotting the following:

Code:
twoway (tsline price, yaxis(2) lcolor(black)) || (tsline volume, yaxis(1) lcolor(gs10)), tline(15dec2017, lp(dash) lc(cranberry))
The command executed perfectly. However, I need to change the size of the y-axes since they get rendered in a font that I can only call humongous. Appending
Code:
xtitle(, size(small)) xlabel(,labsize(small))
works well for the date axis. But putting
Code:
ytitle(, size(small)) ylabel(,labsize(small))
only makes the size of one y-axis small. How do I get Stata to reduce the size of the other axis as well?

Thank you so much in advance!