  The focusing cubic wave equation in three spatial dimensions has the explicit
solution $\sqrt{2}/t$. We study the stability of the blowup described by this
solution as $t \to 0$ without symmetry restrictions on the data. Via the
conformal invariance of the equation we obtain a companion result for the
stability of slow decay in the framework of a hyperboloidal initial value
formulation. More precisely, we identify a codimension-1 Lipschitz manifold of
initial data leading to solutions which converge to Lorentz boosts of
$\sqrt{2}/t$ as $t\to\infty$. These global solutions thus exhibit a slow
nondispersive decay, in contrast to small data evolutions.
