Generalizing from 1-category theory, there's a simple definition of a "naive complex" in a stable $\infty$-category. Considering bounded positive graded chain complexes, they are a sequence of maps $$ A_n \xrightarrow{d_n} A_{n-1} \xrightarrow{d_{n-1}} \ldots \xrightarrow{d_1} A_0 $$ with the property that $d_k d_{k+1} \simeq 0$. If I've not made any errors, then at first blush they seem to have a reasonable theory, along with a nice "realization" given by iteratively taking homotopy cofibers: $$ |A| = \mathrm{cofib}(\mathrm{cofib}(\ldots) \to A_0) $$ that parallels taking the total complex of a bicomplex. This realization can also be given by the colimit of the diagram $$ A_n \rightrightarrows^{d_n}_0 A_{n-1} \rightrightarrows \ldots \rightrightarrows^{d_1}_0 A_0$$ --- However, naive complexes don't seem to be studied. Instead, in Higher Algebra, Lurie proves a Dold-Kan correspondence stable $\infty$-category asserting equivalences between the categories of: * Simplicial objects * Filtered objects (i.e. arbitrary $\mathbb{Z}_{\geq 0}$-indexed diagrams) * upper-triangular array with zeroes along the diagonal, in which every square is a pushout and it is this last sort of thing that Lurie calls a complex. (Specifically, a $\mathbb{Z}_{\geq 0}$-complex) It is only when looking at the homotopy category does Lurie say anything about a correspondence between simplicial objects and naive complexes. So my question is whether this is an oversight; i.e. > Is the $\infty$-category of simplicial objects in a stable $\infty$-category equivalent to the $\infty$-category of (unbounded, positively graded) naive complexes? and if the answer is no, what goes wrong?