NOVELTY - Styrene based polymer (A) comprising one or more optionally substituted styrene repeating units and one or more (hetero)aryl repeating units (I), is new.    USE - (I) are useful as a hole transport layer, a hole injection layer, a hole blocking layer, an emitter layer, electron blocking layer, electron transport layer, electron injection layer, emitter layer, a charge generation layer, photon absorption layer and/or an interlayer, in an electronic device comprising an organic electroluminescent device/diode, organic polymeric device/diode, organic integrated circuit, organic field-effect transistor, organic thin film transistors, organic light-emitting transistor, organic solar cell, organic optical detector, organic photoreceptor, organic field-quench devices, light-emitting electrochemical cell or organic laser diodes (all claimed).    ADVANTAGE - (A) exhibit good film-forming properties and high stability.    DETAILED DESCRIPTION - Styrene based polymer (A) comprising one or more optionally substituted styrene repeating units and one or more (hetero)aryl repeating units of formula (Y1-L1n-Ar1) (I), is new.    Y1 = a link to the polymer backbone;    L1 = optionally substituted (hetero)aromatic or non-aromatic group, or alkylene, alkenylene or alkynylene group;    n = 1-3;    Ar1 = fused 10-40C, preferably 10-24C-(hetero)aromatic ring system, where at least one ring atom is a heteroatom, comprising N, O and/or S, and the remaining atoms are carbon atoms, which are optionally substituted with one or more R; either    R = linear 1-40C-alkyl, -alkenyl, -alkynyl or (thio)alkoxy or branched or cyclic 3-40C-alkyl, -alkenyl, -alkynyl or -(thio)alkoxy (both optionally substituted by one or more radicals R10, where one or more non-adjacent CH2 groups are optionally replaced by R10C=CR10, CC, Si(R10)2, Ge(R10)2, Sn(R10)2, C=O, C=S, C=Se, C=NR10, P(=O)(R10), SO, SO2, NR10, O, S or CONR10, and one or more H atoms are optionally replaced by F, Cl, Br, I, CN or NO2), or 5-60 membered (hetero)aryl, 5-40 membered (hetero)aromatic ring system and/or 5-40 membered (hetero)aryloxy (all optionally substituted by R10), H, D, F, Cl, Br, I, N(R10)2, N(Ar11)-2 , C(R10)=C(R10)Ar11, Si(R10)3 or B(OR10)2; or    two or more R = mono- or polycyclic, aliphatic or aromatic ring system, where at least one R is K1-(Ar11)m;    m = greater than or equal to 1;    R10 = H, D or 1-20C-aliphatic or aromatic hydrocarbyl;    K1 = a covalent bond, optionally substituted (hetero)aromatic or non-aromatic group or an alkylene, alkenylene or alkynylene group; and    Ar11 = optionally substituted (hetero)aryl, (hetero)aryloxy, (hetero)aromatic ring system or a non-aromatic group.    INDEPENDENT CLAIMS are included for:    (1) a blend comprising (A) and one or more oligomeric, polymeric, dendrimeric or low molecular weight compound;    (2) a formulation comprising (A), or the blend in one or more solvents; and    (3) substituted anthracene compounds of formula (III).    R1-R9 = R; and    Z = polymerizable group, preferably oxetane, epoxy, vinyl, vinyl ether, vinyl ester or vinyl amide.