I don't like very much the superscripts, subscripts and comma position in equation (1).
In equation (2) I've made the superscripts and subscripts smaller but still I don't think it is completely good.
Any idea to improve this equation?
\documentclass[11pt,openright]{book}
\usepackage[T1]{fontenc}
\usepackage[latin9]{inputenc}
\pagenumbering{gobble}
\usepackage{mathtools}
\usepackage{relsize,amsmath}
\usepackage{amssymb}
\begin{document}
\begin{equation}
\mathrm{MRC}^{t}=\max\left\{\mathrm{VaR}_{0.99}^{t-1,10}, \, \frac{k}{60}\sum_{i=1}^{60}\mathrm{VaR}_{0.99}^{t-i,10}\right\}
\end{equation}
\begin{equation}
\mathrm{MRC}^{t}=\max\left\{\mathrm{VaR}_{\mathsmaller{0.99}}^{\mathstrut \mathsmaller{t-1,10}}, \, \frac{k}{60}\sum_{i=1}^{60}\mathrm{VaR}_{\mathsmaller{0.99}}^{\mathstrut \mathsmaller{t-i,10}}\right\}
\end{equation}
where MRC is the Market Risk Capital required at time $t$ and $\text{VaR}_{\alpha}^{j,h}$ is the day $j$'s Value at Risk calculated
with a holding period of $h$ trading days and an $\alpha$ confidence level
\end{document}



