  Recently, experimental collaborations have reported $\mathcal{O}(10)$ upper
limits on the signal strength of four-top production at the LHC, which already
leads to competitive constraints on certain type of top-quark operators. On the
other hand, developments in the $b$-jet charge tagging algorithms open up new
possibilities for the direct measurement of the top-quark width. In this talk,
we briefly discuss some recent studies in these two directions.
