  We evaluate the implications of LHC and LEP/SLC measurements for the
electro-weak couplings of the top and bottom quarks. We derive global bounds on
the Wilson coefficients of ten two-fermion operators in an effective field
theory description. The combination of hadron collider data with $Z$-pole
measurements is found to yield tight limits on the operator coefficients that
modify the left-handed couplings of the bottom and top quark to the $Z$ boson.
We also present projections for the high-luminosity phase of the LHC and for
future electron-positron colliders. The bounds on the operator coefficients are
expected to improve substantially during the remaining LHC programme, by
factors of $1$ to $5$ if systematic uncertainties are scaled as statistical
ones. The operation of an $e^+e^-$ collider at a center-of-mass energy above
the top-quark pair production threshold is expected to further improve the
bounds by one to two orders of magnitude. The combination of measurements in
$pp$ and $e^+e^-$ collisions allows for a percent-level determination of the
top-quark Yukawa coupling, that is robust in a global fit.
