I have looked in symbols file and tried various forms of $\exists$ with various fonts but I always get something that appears very thin. As if there is no bold version. Is there a way of approximating a bold version? I am assuming this applies to many of logic symbols.
I had a similar question, which was closed due to lack of clarity. There the suggestion was to take letter E and rotate or flip it. The results are not that satisfactory.

\documentclass{article}\usepackage{bm}\begin{document}$\exists\bm{\exists}$\end{document}. However, in most fonts, the thin\existsis what you want; the font designers know why they make it thin: it shall be thin, thicker would be really ugly. – yo' Jul 10 '16 at 19:23\reflectbox{E}:) – Manuel Jul 10 '16 at 23:36