[Tex/LaTex] Product symbol in bold

Question

why the prod command do not display bold character like in the picture below

here the code and my output

\usepackage[showframe]{geometry} 
\usepackage{amsmath} 
\usepackage{amsfonts} 
\usepackage{amssymb} 
\usepackage{mathtools} 
\usepackage[mathscr]{euscript} 
\usepackage{verbatim} 
\usepackage{vector} 
\usepackage{epstopdf} 
\usepackage{epsfig}
\usepackage{graphicx} 
\usepackage[english]{babel} 
\usepackage{float} 
\usepackage{varioref} 
\usepackage[latin1]{inputenc}
\usepackage[sonny]{fncychap}
\usepackage {minitoc} 
\usepackage{fancyhdr}
\usepackage{csquotes}
\usepackage{array}
\usepackage[authory ar,comma,longnamesfirst,sectionbib]{natbib}
\usepackage[super]{natbib} 
\usepackage[square]{natbib}
\usepackage[colorlinks=true,linkcolor=black, citecolor=blue, urlcolor=blue]{hyperref}
\usepackage{numcompress} 
\usepackage{adjustbox}
\usepackage{multirow} 
\usepackage{booktabs} 
\usepackage{tabulary} 
\usepackage{float} 
\usepackage{tabularx} 
\usepackage[T1]{fontenc}
\usepackage{booktabs}
\usepackage{eurosym} 
\usepackage[figurename=Fig.]{caption} 
\usepackage{anyfontsize}
\usepackage{stackengine}



\[
P^{\circ M,j}_{t+s\textbar{t}}(k)\equiv 
\displaystyle{\prod_{i=1}^{s}} \Pi^{\theta}_{m,t+s-i} 
\bar{\Pi}^{s(1-\theta)}_{m} P^{\circ{M,j}}(k) 
\]

my output

Answer 1

Use the following package \usepackage{bm} and code with \bm with required symbol like below:

\[
P^{\circ M,j}_{t+s\textbar{t}}(k)\equiv \displaystyle{{\bm\prod}_{i=1}^{s}} \Pi^{\theta}_{m,t+s-i} \bar{\Pi}^{s(1-\theta)}_{m} P^{\circ{M,j}}(k) \]