  Spin Matrix theory describes near-BPS limits of $\mathcal{N}=4$ SYM theory,
which enables us to probe finite $N$ effects like D-branes and black hole
physics. In previous works, we have developed the spherical reduction and spin
chain methods to construct Spin Matrix theory for various limits. In this
paper, by considering a supercharge $\mathcal{Q}$ which is cubic in terms of
the letters, we construct the Hamiltonian of the largest Spin Matrix theory of
$\mathcal{N}=4$ SYM, called the PSU$(1,2|3)$ Spin Matrix theory, as $H =
\{\mathcal{Q}, \mathcal{Q}^\dagger \}$. We show the resulting Hamiltonian is
automatically positive definite and manifestly invariant under supersymmetry.
The Hamiltonian is made of basic blocks which transform as supermultiplets. A
novel feature of this Hamiltonian is its division into D-terms and F-terms that
are separately invariant under PSU$(1,2|3)$ symmetry and positive definite. As
all the other Spin Matrix theories arising from $\mathcal{N}=4$ SYM can be
acquired by turning off certain letters in the theory, we consider our work as
revealing the "Panorama" of Spin Matrix theory.
