  We present magneto-transport calculations for YBa$_2$Cu$_3$O$_{7-\delta}$
(YBCO) materials to show that the electron-like metallic chain state gives both
the negative Hall effect and in-plane anisotropic large Nernst signal. We show
that the inevitable presence of the metallic 1D CuO chain layer lying between
the CuO2 bilayers in YBCO renders an electron-like Fermi surface in the doping
range as wide as p=0.05 to overdoping. With underdoping, a pseudogap opening in
the CuO2 state reduces its hole-carrier contribution, and therefore the net
electron-like quasiparticles dominate the transport properties, and a negative
Hall resistance commences. We also show that the observation of in-plane
anisotropy in the Nernst signal - which was taken as a definite evidence of the
electronic `nematic' pseudogap phase - is naturally explained by including the
`quasi-uniaxial' metallic chain state. Finally, we comment on how the chain
state can also lead to electron-like quantum oscillations.
