The covariance matrix for the kinematic bins matrix of the $D_s^+$ production asymmetry measured using the $\sqrt{s} =7$ TeV data set (corresponding to Table 2). The statistical and systematic uncertainties are combined. The kinematic bins are indexed as follows: the three rapidity bins, y, in the range from 2.0 to 4.5 are indexed with $i_y$ ranging from 0 to 2 with the following bin edges: 2.0, 3.0, 3.5, 4.5. The four $p_{\rm T}$ bins in the range from 2.5 to 25.0 GeV/c are indexed with $i_{p_T}$ from 0 to 3 with the following bin edges: 2.5, 4.7, 6.5, 8.5, 25.0 GeV/c. The index of a kinematic bins is then given by: $i_{\rm bin} = 4 \times i_y + i_{p_T}$.

The inclusive $D_s^{\pm}$ production asymmetry is measured in $pp$ collisions collected by the LHCb experiment at centre-of-mass energies of $\sqrt{s} =7$ and 8 TeV. Promptly produced $D_s^{\pm}$ mesons are used, which decay as $D_s^{\pm}\to\phi\pi^{\pm}$, with $\phi\to K^+K^-$. The measurement is performed in bins of transverse momentum, $p_{\rm T}$, and rapidity, $y$, covering the range $2.5